The 3kW heating element is standard for instant geysers in India, but you should check the type and material of the heating element. Incoloy or copper heating elements are known for their durability and efficiency. Otherwise glass coated heating elements are the best. Only AO Smith provide glass coated heating element in Instant geysers in India.

Instant geyser must have safety features like a thermostat to prevent overheating and a pressure relief valve to release excess pressure. As the 3kw is considered high power which put a lot of load on wiring of the house specially old houses with decade old wiring. An ELCB inbuilt instant geyser are also need of the hour to avoid electric shock. Better to connect elcb plug/top separately to geyser.

Racold Pronto Pro 3L 3KW Vertical Instant Water Heater (Geyser) | Faster Heating | Suitable for High Rise Buildings | Italian Design|3 Levels of Safety|Convenient for Kitchen & Bathroom Applications
  • PUF INSULATION: the dense and thick insulation in the tank effectively retains heat, improving energy efficiency and lowering electricity costs
  • FASTER HEATING: the high-capacity heating element ensures rapid access to hot water
  • AUTO CUT OFF: the stem-type thermostat and cutout feature provide automatic temperature control and added safety for your water heater
  • NO BACK FLOW: the anti-syphoning system prevents water from flowing back into the container, thus avoiding dry heating
  • HIGH PRESSURE RESISTANCE: the water heater has high pressure withstanding capacity, which makes it suitable for high-rise buildings and high pressure pump applications
AO Smith EWS-5 White Instant Geyser 5 Litre With 3kW Express Heating | High Rise Building Bathroom & Kitchen geyser | UL Rated Wiring & Pressure Relief Valve For Ultimate Safety | 5 Year Tank Warranty
  • INSTANT HOT WATER HEATER FOR YOUR HOME: Experience the comfort of instant water heater technology with our 3000-watt element. Whether for your bathroom or kitchen, this instant water heater delivers hot water in seconds, perfect for cold mornings.
  • DURABLE STAINLESS STEEL GEYSER 5 LTR: Our geyser 5 litre with a stainless steel tank is built to resist corrosion even in hard water. Designed for long-lasting performance, this 5 litre geyser ensures you enjoy dependable hot water every day.
  • ADVANCED SAFETY FEATURES FOR YOUR FAMILY: Stay protected with our electric geyser featuring a 5-level safety shield. From overheating control to a rust-proof body, this instant water heater for bathroom guarantees total peace of mind for you and your loved ones.
  • HIGH-PRESSURE READY FOR HIGH-RISE HOMES: Perfect for high-rise living, our water heater 5 litre handles up to 6.5 Bar pressure effortlessly. This hot water geyser for bathroom ensures consistent performance, even in multi-story buildings.
  • WORRY-FREE WARRANTY FOR YEARS TO COME: Invest in confidence with a 5-year tank warranty and 2-year product warranty by AO Smith. Our instant water heater is backed by comprehensive coverage, ensuring you get the best experience without worry.
Candy CM3LV White Geyser 3 Litre 3KW Fast Heating Glass-Lined Instant Water Heater ABS Out Body for High-rise Building 8 Bar Instant Geyser for Kitchen& Bathroom, Wall-Mounting
  • INSTANT HEATING: Indulge in the pleasure of warm water with our advanced water geyser! It is equipped with a 3L water tank and a powerful 3KW high-efficiency heating element. In just a few minutes, it can quickly heat up the water, reaching a maximum temperature of 55℃. No matter when you need it, you can always enjoy a pleasant and comfortable hot water experience, meeting the daily needs of you and your family
  • Perfect for Kitchen and Bathroom: You don’t have to worry about the high costs and space occupation brought by a large-capacity water geyser. Our compact geyser 3 ltr is the perfect choice for you. It is specifically designed to meet your short-term hot water needs, ensuring both daily practicality and a touch of life’s ritual. Whether you need to quickly clean the greasy tableware or comfortably wash certain parts of your body, it can promptly supply hot water at an appropriate temperature
  • COMPACT, STYLISH, AND SPACE-SAVING DESIGN: Our heater for bathroom features a body with pure white as the main color tone, complemented by lively polka dot blue elements, infusing your bathroom and kitchen with the refreshing vibe of the beaches in Goa. The overall design is simple yet exudes a modern touch, effortlessly blending in with various home decoration styles without any sense of incongruity. With its compact shape and flat design, it can be ingeniously installed in confined spaces
  • Suit for High-rise Building: With an exceptional pressure-bearing range of 0.05bar to 8bar, this water heater 3 litre is truly tailor-made for complex water pressure environments! When you live above the 15th floor, many water heaters can’t start due to low water pressure. However, our product can operate smoothly even under a low water pressure of 0.05bar. Moreover, when faced with a powerful water pressure of up to 8bar, it can handle the situation with ease
  • Durable Water Geyser with Glass-lined: Our water heater uses high-quality enamel materials and exquisite craftsmanship to evenly cover the inner tank with a sturdy enamel coating. This coating is just like a solid shield, which can effectively resist the erosion of the inner tank caused by various water qualities. Its anti-corrosion ability is more than three times that of ordinary products. It is especially suitable for hard water conditions
Racold Altroi+ DN 6L 3KW Vertical 5 Star Instant Water Heater (Geyser) White, with Free Standard Installation & Pipes | Smart LED Ring|Free Electric Plug| for Kitchen & Bathroom, Wall Mounting
  • High Pressure Resistance: Your water heater has high pressure withstanding capacity, which makes it suitable for high-rise buildings and high pressure pump applications
  • Temperature Regulation Knob: An easy control knob through which you can regulate heating of water as per your requirement
  • Safety Plus: Three levels of safety against high temperature and pressure, provided by a hightech adjustable thermostat, cut-out and multi function safety valve according to international standards
  • Customized Application : It’s a unique, novel and first of its kind feature in the Instant water heater segment helps you in optimizing water heater usage . You can select ‘KITCHEN’ or ‘BATHING’ mode based on the intended hot water application
  • Smart LED Ring : The Smart LED Ring range senses when hot water is ready for bath, or other application and notifies user by changing LED color from blue to red
NEXOMS Cup Type Heating Element ISI Marked 3KW Compatible for 3 Litre – 6 Litres Instant Geysers
  • Tube Material: Anti-Corrosive Copper
  • Power: 3KW
  • Heavy Quality ISI Marked Element
  • Compatible for Portable Geysers and Instant Geysers 3 Litre to 6 Litres
Crompton Solarium Neo 3-Litre, 3KW Instant Water Heater/Geyser with Rust Free ABS Body (Ivory)
  • PRODUCT: Crompton’s energy efficient instant water heater with rust proof ABS body
  • TECHNICAL SPECIFICATIONS: Wattage: 3000 W; Capacity: 3L; Pressure 6.5 bar
  • 4 LEVEL SAFETY: Capillary Thermostat, automatic thermal cut-out, pressure release valve and fusible plug
  • ANTI-SIPHON PROTECTION: Designed to prevent any backflow of water and protect the heating element from dry heating damage
  • QUALITY COMPONENTS: ISI marked nickel coated special element to provide resistance against scale formation
Bajaj Shield Series Aerono 1L 3KW Instant Water Heater/Geyser For Home|Non Stick Heating Element|Withstand 6 Bar Pressure|Shock Resistant & Rust Proof|Withstand 4.5KV Surge Voltage|3-Yr Warranty|White
  • Bajaj DuracoatTM Non stick heating element Bajaj DuraNteTM Thermostat Bajaj VoltageProTM – Withstand 4.5KV surge Voltage
  • Shock resistant & rust proof Engineering Thermoplastic body Indicator for power on & heating function
  • Multiple safety system High Grade SS Tank
  • BIS Approved ISI marking Fire Retardant cable
  • Tank suitable to withstand 6 bar pressure
Crompton InstaBliss 3-L Instant Water Heater (Geyser) with Advanced 4 Level Safety (White), Wall Mounting
  • Rust Proof Outer Body: High quality Thermoplastic engineering prevents rusting of the outer body
  • Food Grade Inner Tank: 304 Grade Stainless Steel Inner Tank; also suitable to be used in the kitchen
  • Powerful Heating: 3000-Watts Copper Heating Element for 33% faster heating
  • 4-Level Safety: Thermostat, automatic thermal cut-out, pressure release valve and a fusible plug to ensure complete safety
  • Withstands a pressure of 6.5 Bar: Suitable for high rise buildings and pressure pump applications

Another thing to check is pressure bar capacity of inner tank specially if you like high rise buildings as water pressure can be much more for tank to withhold. You can also consider 4.5kw instant geysers if the house is fairly new with new wiring.