I have been using the Reliance JioFi since December 2016, add I would strongly suggest people not to buy it. I will try to compile the reasons in the form of a list.
1) I was using the RS 509 plan, which gives the user 2GB data every day for a month(They have extended their validity for three months, but it is only a temporary offer). However, I used to use only around 1.5 GB data and my limit used to get exhausted. After extensive research, I found out that the JioFi is just a hotspot device and not a broadband device. Therefore, the waste data that you use while throwing the hotspot connection all around, is also counted. For me, this was not at all fair.
2) Speed are very very extremely slow and not at all reliable.
3) Calls are placed 75% of the time. It is a very unreliable service for calling. Many times I have been stuck and the phone would not connect and people have gotten upset.
All in all, I have stopped using this connection and was not at all satisfied by it.