2600 = 50$ ! Which is really low budget but ok fine!
9600GT 512 Mb Seems Fine, But i dnt think it will come in your budget! Not In India! Because It Costs 4000 Rs!
Now, The Cards which will come in your budget are
1. ATi Radeon 5450 - 2,200 Rs
2. Nvidia 8400GS - 2,500 Rs
3. Ati Radeon 4650 - 2,600 Rs
Out Of This, I Would Suggest you to buy the 5450! Thats The Best You Can Get For That Money!