Am on the 950 plan. Its enough for me, but still the FUP irritates a lot. Also before getting the plan, check if BSNL can even provide speed upto 4Mbps. I know of many people in the same plan, but they don't even get 2Mbps out of it.
If Reliance is available in your area, see these plans - Welcome to Reliance Communications. They look quite good.
Very true. I too use the 950 plan but i only get 1.72 mbps, when complained about speed, nothing happens. And 8GB is not enough, believe me. Mine finishes in just 1 week (Usage-Youtube,forums,facebook,mw2/cs). And as you mentioned your average download pm is 100gb it wont be enough for you. The post FUP speeds are very bad and fluctuate very much. I myself am switching to Hathway and will take either 1mbps unlimited or 5mbps 25gb.But i siggest you try the plan for 1 month and decide.
[P.S]- after FUP, any youtube video struggles even to load in 240p
4 Mbps upto 20 GB, thereafter 1Mbps @899 from the link by Vignesh. Seems to good to be true, OP get this if available. (IDK about Reliance)