I had used reliance about 3-4 years ago and then I changed to airtel due to numerous reasons.
The number of base stations of reliance are very less in india and in few of the cities there are no tower at all. So if you travel to some remote areas then you might face low coverage network problem and might not able to use any service.
Reliance calling is also not much good and efficient because many times I have faced call problems like automatic call disconnect while on call, no voice from the receiver, voice breakage, cross talk.
Reliance data is an another big issue. Reliance data rates are same as other cellular networks but the speed is very low when compared to other networks and even reliance 3g is also very slow. Video gets buffered for about half an hour.
Reliance charges customer for many things without any purpose and when we call them they say that they will credit back the balance soon but no money is credited again and when we say that you have detected the balance unfortunately, they blame us that we have only activated the plan.