Hi Tarun,

The admissions are based on entrance exam or the  marks scored in +2 level. The admission process is different for different colleges and different states. we can guide you further if you mention your town, state name or colleges you are interested in the comment section below.

you can find some of the top universities in the below link

https://university.careers360.com/articles/top-agricultural-universities-in-india-2016

Hope this helps.

Good Luck!!