I'm also an Indian
First of all, 9400GT isn't a gaming card and won't play those games.
Well HD4850 costs Rs 6000 and HD5750 is way out of your budget.
HD4850 will play all the games you mentioned.
If you can stretch your budget to Rs6000 then there is no card that beats HD4850 for the price.
Else you ca get a Nvidia Geforce 9800GT for Rs5500 or Nvidia 9600GT for Rs 4500-5000.
BTW, What is your monitor's native resolution? And which SMPS do you have?