Video card upgrade suggestion - Geforce GT 210?

Currently my pc specifications are:

CPU:Pentium 4- 2.8 GHz


Ram:Kingston 512 MB

Graphics Card:Nvidia Rina Model TNT2 Model - 16Mb ONLY :-(

I want to play games like need for speed carbon , undercover and shift.Do I need to upgrade my video card to GT 210 or any other video card.Please suggest something.Budget Range (6000 PAK Rupees).