I got a Jio Sim for free this January obviously for its free data and calling services. I got it so late because I had gotten no good reviews from the people who were using this network then, and also I had a single sim phone. I bought a dual sim phone so thought would use this jio sim as the second sim so that I would have my other network sim ( Airtel) , incase ( and by that I mean all the time) the jio reviews are legit. And indeed they all were. I literally never get any signals in case I want to make a call through without any disturbance and then have to ultimately hang up and make the call again with another sim. I have never been able to make a call with clear voice reception on both ends. Data service is not that amazing but it does atleast work better than the calling one. The only thing that has been good about this is that it was free. I have a WiFi at home and don't get to use the Internet service so this proved to be completely useless for me.
