Before its commercial launch , its giving people free sims so that people can enjoy their network before launch.
Its not all , they are giving free internet , free voice call & free sms for 3 months . Its very good.
Its only works on 4g network and also calls works on 4g so their is not any need of recharging for call. I have tested its download speed in 3 different areas and the speed which I get is simply awesome.
Jalandhr - 10-30 MBps
Dehradun - 6- 18 MBps
Delhi - 4 - 20 MBps
So its great you are getting this much speed and this is for free.
So dont belive in me go and try by urself afterall its free.