Guys sorry to say but you are all going about it slightly off direction. Having all supported lte bands unlocked and volte feature enabled in your phone is simply not enough. VOLTE works only and only on devices that the carrier explicitly supports. Your imported handsets are unlocked but model numbers would never match on your Indian carrier. You can benefit from LTE data and jio4gvoice app. Sent from my MI 5 using Tapatalk