If you got non-VoLTE 4G handset to be used with Jio sim then here are steps to activate jio sim on your non Volte 4G phone. 
Download “Jio 4G Voice” App
Check internet settings check APN is set to “jionet”
Make sure mobile data is on and wifi is off.
Activate Jio 4G voice app after inserting jio sim card.
Dial 1977 from Jio4GVoice app to activate the sim.
One disadvantage of using jio sim card on non volte phone is that to receive or make calls one need to have mobile data always ‘on’ and wifi always ‘off’. Jio for now doesn’t allow calls on wifi via JIO4G Voice app. We hope this functionality to be activated soon else non-volte jio users are on major disadvantage.