Hello and welcome to the forum @Aneeshsonkar!
I'm sorry to hear about the trouble you are having with your phone.
Do mean that you are unable to make any calls at all with your phone? If that is the case, are you able to send text messages or connect to a mobile network? Check under Settings > More > Mobile networks > Network operators, are you able to connect to a network here? I would also recommend that you, if possible, try using another SIM-card in your phone.
However, if your device is branded to a specific operator and you recently switched to Jio you will need to contact your previous service provider in order "unlock" your phone to other network operators.
Let me know how it goes!
