@mandar5
u can play FEAR @1024*768 at high settings, but not at extreme setings. U have to scale down 1~2 heavy effects like soft shadows nd pixel doubling.
If u can stretch ur bidget a lil bit more then u can opt for cards which g_goyal2000 suggested.
A 7600GS[6.5k] is a bit more powerful than a 6600GT especially when latest nd future games are concerned which uses more HDR, SM3 etc.
A Zebronics 6800XT 512 MB [7k] berforms better than 7600GS and with 256 bit 512 megs of memory, its a gud performer. U can use more texture intense effects as it has 512megs for all those textures. It performs somewhat near a 7600GT.