I have been using Jio from last 2 months. It were never been able to impress me in terms of call quality or data transfer rate.
If we talk about network coverage, it is the worst service provider, very much similar to reliance communications. If you are at the top of building then you may enjoy the network in relation to good call quality or fine speed of data transfer but if you are roaming in the streets or living at the lower of the building you will feel like hell. Call drop or bad data speed is very common thing.
They are also not so good in terms of services. They seem helpless when you call their customer care.
Charges and billing are attractive but is o no use because if the quality is bad and you are not able to do a call in piece.
Bad experience over all.