Tamil Nadu Agricultural University

In 2017, for B.Sc (Ag), the cut-off will be above 195 as there is heavy competition nowadays due to NEET exam based medical seats. Rest depends upon your community reservation. If you don't get a seat, just add in waiting list. If you are lucky, you will get the seat.
Best wishes.

Please refer to the link provided below for a list of courses offered by Tamil Nadu Agricultural University. You should be able to navigate to a college of your choice using the filters on the web page. Additionally, download the college brochure for further details. Regards.
https://www.shiksha.com/university/tamilnadu-agricultural-university-tnau-coimbatore-23625/courses

Yes, you can pursue B.Sc Agriculture but you should have completed class 12th with science stream. There is an ICAR (Indian Council of Agri Research) scholarship programme for toppers admitted to the degree.