read this post and learn “how To use Jio 4G SIM in 3G phone?”yes it’s possible but you need to do some modification in your 3G phone.
After a long time reliance has been launched their 4G network service on 5 September in INDIA and all of sudden everyone is talking about Reliance JIo 4G networks. It is just because of its Free Unlimited voice calling and free unlimited 4G internet data for everyone. It’s really cool and i am using their free preview offer on my 4G android phone. But every user is not able to use Jio 4G SIM on their phone .because they are not using 4G android phone .so every 3G android phone users are trying to search a decent way to use Jio 4G SIM in 3G phone.