The best GPU under Rs 10,000 is definitely a GTX 750 2GB.
But I will advice you to spend another Rs 500 more and get a GTX 750TI 2GB instead. 500W is more than enough for a GTX 750TI.
Throw out that Odyssey power supply first and get a new one. No good graphics card will run on that power supply. One power surge and it can go kaput, and can also damage your components.
Not sure where the name odyssey came from, but if it is junk then yes replace it with a better unit. A good gpu that does not require more than a good 300 watt psu is the gtx 750ti. Not sure of the cost in your country. about $150 us dollars
From "one Indian to another". I had my own Odyssey fail on me with one rogue power surge in just 7 days. It's the most common no-name el-cheapo power supply in India.
9 out of 10 the OP has a Odyssey 450W.
hay Anish5 you will have to change your power supply to 450w or 400w and the if you wish to spend about 11500rs for your graphics card then you should go for the zotac gtx750ti it is a nice graphics card which could run most of the games.
The best GPU under Rs 10,000 is definitely a GTX 750 2GB.
But I will advice you to spend another Rs 500 more and get a GTX 750TI 2GB instead. 500W is more than enough for a GTX 750TI.