Most famous network provider is now jio after they give free internet, free calls, free sms, everything is free, I use it from November it is really give good service to us but sometime its network lost,
its network is also very good, its call quality is full HD, you can listen very clear sound when you call but sometime its network fails to call or doing anything but its network coverage is very good you can call from your inside home or in metro.
customer service is good they solve your problem quickly.
reliance jio is not taking any charges or any billing they provide everything to us till march 2017.