[Q] 7950 Vs 7870 Vs GTX 660Ti

Well, overall the 7950 is better. But, when your talking differences of something like $70 (And AMD tend to be very expensive in India), then you can't go wrong with a 660ti. A 660ti also beats a 7870.

It will also be helpful if you link your power supply, and the particular models of cards you are looking for.