I need help choosing a motherboard for my processor (i.e. Core2Duo) as my old motherboard is not working.
It should be DDR3. I would like to know which is highest rated brand now and where do I compare prices (in Indian Rupees).
There are plenty of good brands, ASUS, ASRock, Gigabyte to name but a few, and anything but the very cheapest motherboards will be well designed and well made. The differences will be down to chipsets (premium and more recent chipsets tend to offer a small performance boost).
However, compatibility is clearly of the utmost importance here, so it would be better for you to define what you mean by "better" (more expansion slots? more USB 3.0 connectors? Built in 802.11n? something else?) and then look at different motherboards. If you end up with a short list and would like our opinion on them, post the list and your priorities, as mentioned above, and I'm sure you'll get plenty of responses.
Asus is a good brand that makes good quality motherboards.
Although you are free to make your won choices.
You can get following -
Asus P5G41T-M LX
Gigabyte GA-G41M Motherboard
Maybe take the time to enlighten us on what hardware you have in your box and whether oir not you intend to keep it as it will effect the answer that will suit you best.