I have 3 options like
1. Canon EOS1100D
2. Nikon D3100 / D5100
3. Sony SLT A37
So, please advice me in this and I hope can you give reple as soon as possible.
I would personally prefer Canon 1100D for reasons like resale value, up gradation, lens availability, accessories.. and canon showrooms / support.
But quality wise all companies are more or less equally good for beginning photographers.