I am stay in kolkata and I am using Airtel number it is very good network in our region. 2G, 3G, and 4G very good service to other network no call drop and alwayys network on. I am surprisingly when I am traveling to metro rail other network not show tower but airtel show tower.
Airtel 1st who has been lunched 4G network and very first internet. Airtel also provide airtel money thats you can send your money through mobile.