Hi i am also from India, i got one PC ready for same price recently too.
i can only suggest you one build for 40k
FX 6300 - Rs 7500
Gigabyte 970A DS3 - Rs 6000
Ram: Kingston HyperX 1x4 GB - Rs 2600
HDD: WD Caivar Blue - Rs 3500
GPU: 650TI Boost 2GB Asus - Rs 13000
Case: Cooler Master Elite 311 - Rs 2100
Dvd writer - Rs 1100
PSU: Corshair CX 500M - Rs 3800
Total: Rs 39600
thats what fit mostly in your budget nothing better can be expected at that.
You can play at good FPS for that Price
Edit: to above this isnt really 600. its like $500 Budget + $100 Tax. And what you see in foreign is much costly here in India.
The prices i mentioned above has been inquired from a local retailer and FlipKart which resembles near about same.