I purchased my phone from Qatar. in India I have airtel and Vodafone SIM. airtel supports volte. but after requesting Vodafone, received volte. I think you need to check with network operator.
There is no need to flash the Firmware. Most of the time Any Mobe purchases from a Particular Network operator , they lock ot to their network. So when going from one UAE to India . May or may not work the Indian SIM in your Mobile. There are people in India who will unlock such Network Locked handset. After that any SIM can be used in Mobile. For Jio to work in any Mo file its MY JIO ,JIO SMS & JIO call. Apps have to be installed. And configures those apps with all Yes. Option and restart. Only JIO has VOLTE feature in India. What other Operator say they have VOLTE. But it dosent have that Net speed and call Smoothnees as to what JIOs VOLTE has.
