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.

Havells Instanio 3-Litre  3KW Instant Water Heater (Geyser) White Mustard, Wall Mounting
  • Type: Instant ; Capacity: 3 Litres; Wattage: 3000 Watts; Pressure: 6.5 Bars4 Level Safety : Thermostat, Automatic Thermal Cut-Out, Pressure Release Valve and Heating Indicator
  • LED : Temperature Sensing Color changing LED Indicator for real-time hotness of the water
  • Outer Body: Rust and shock proof Plastic outer body for long life
  • Heating Element : Copper heating element offers superior heating performance with its excellent resistance to both oxidation and carbonization at high temperature setting and resists corrosion against extreme and hard water conditions
  • Inner Tank : Extra thick Stainless Steel Inner tank of superior 304 Level grade​
Bajaj Splendora 3 Litre 3KW IWH Instant Water Heater (Geyser), White
  • ABS outer body with SS tank
  • Copper heating element with efficient longer life
  • Suitable for 6 bar pressure
  • Unique Weldfree joint in outer metal body
  • It come with fire retardent cable and neon indicator for heating
Racold Pronto Pro 3L 3KW Vertical Instant Water Heater (Geyser) | Faster Heating | Suitable for High Rise Buildings | Italian Design | 3 Levels of Safety | No Back Flow of water | Rust Proof Body
  • PUF Insulation: The high density and thick PUF in your water heater ensures retention of internal heat and temperature and resulting in better energy efficiency and reduced electricity bills
  • Faster Heating: The high power heating element ensures you get hot water in no time
  • High Pressure Resistance: High pressure withstanding capacity makes it suitable for high rise buildings and high pressure pump applications
  • Safety Plus: Pronto Pro provides three levels of safety against high temperature and pressure, provided by a high tech adjustable thermostat, cutout and multifunction safety valve conforming to international standards
  • Auto Cut off: Stem-type thermostat and cutout ensures automatic temperature control and extra safety for your water heater
Crompton Solarium Vogue 3-Litre, 3KW Instant Water Heater/Geyser with free Installation & Pipe (White and Turquoise Blue)
  • Highgrade Stainless steel weldless Tank to protect from corrosion, rust-proof body
  • ISI marked powerful copper heating element that allows fast water heating
  • Anti siphon protection prevents back flow of water from the Tank protecting the heating element from dry heating
  • 6.5 bar pressure suitable for high buildings for use in Bathrooms, Office Pantry, Kitchen, Automatic Shut Off : Yes
  • Advanced 4 level safety with a high precision thermostat and pre-set thermal cut-out
Havells Instanio 1-Litre 3KW Instant Water Heater (Geyser), White Blue, Wall Mounting
  • Type: Instant ; Capacity: 1 Litre; Wattage: 3000 Watts; Pressure: 6.5 Bars ;4 Level Safety : Thermostat, Automatic Thermal Cut-Out, Pressure Release Valve and Heating Indicator
  • LED : Temperature Sensing Color changing LED Indicator for real-time hotness of the water
  • Outer Body: Rust and shock proof Plastic outer body for long life
  • Heating Element : Copper heating element offers superior heating performance with its excellent resistance to both oxidation and carbonization at high temperature setting and resists corrosion against extreme and hard water conditions
  • Inner Tank : Extra thick Stainless Steel Inner tank of superior 304 Level grade​
Racold Pronto Neo 3L 3Kw Vertical Instant Water Heater(Geyser), White | Faster Heating | Italian Design |Suitable for High Rise Buildings | 3 Levels of Safety | Rust Proof Body | Fire Retardant Cable
  • PUF Insulation: The high density and thick PUF in your water heater ensures retention of internal heat and temperature and resulting in better energy efficiency and reduced electricity bills
  • Faster Heating: The high power heating element ensures you get hot water in no time
  • High Pressure Resistance: High pressure withstanding capacity makes it suitable for high rise buildings and high pressure pump applications
  • Safety Plus: Pronto neo provides three levels of safety against high temperature and pressure, provided by a high tech adjustable thermostat, cutout and multifunction safety valve conforming to international standards
  • Auto Cut off: Stem-type thermostat and cutout ensures automatic temperature control and extra safety for your water heater
Racold Altroi+ 3L 3KW Vertical Instant Water Heater (Geyser) White, with Free Standard Installation & Pipes | Smart LED Ring | Free Electric Plug |Kitchen & Bath Mode | Faster Heating |Italian Design
  • 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
Polycab Etira 1Ltr 3 Kw Electric Instant Water Heater (Geyser) with Anti rust tank, powerful heating element, multiple layer safety, ISI certified with 5 years inner tank Warranty (White)
  • Polycab Water Heater is Loaded with features like rust-proof engineering thermoplastic outer body, powerful and highly efficient heating element, capillary thermostat, sleek and compact design
  • Polycab Water Heaters can be installed in your bathroom, kitchen and other similar areas inside your homes.
  • Warranty: 2 Years on Product and 7 Years on Inner tank
  • PACKAGE CONTENTS: 1 unit of Polycab Instant Water Heater, Instructions Manual and Warranty Card
  • For Service Request and Complaints : 1800267008
Anchor by Panasonic Astra 3L Geyser, 3KW Instant Water Heater (Geyser) with Glassline Inner Tank (Free Installation) (White and Blue)
  • Package contains : 3L Instant Water heater
  • Type : instant, capacity : 3 litres, wattage : 3000/4500 Watts, working Pressure 0.6Mpa.
  • Tank is made from Stainless Steel which increases durability of the product, Heating element made of copper
  • Safety Valve opens for water to flow out on exceeding a pre-set pressure
  • Thermostat and cut-out conforms to international standards, ensuring enhanced safety
Racold Altroi+ DN 6L 3KW Vertical 5 Star Instant Water Heater (Geyser) White, with Free Standard Installation & Pipes | Smart LED Ring | Free Electric Plug | Kitchen & Bath Mode | Faster Heating
  • 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

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.