Dear Monisha, generally for pursuing M.Tech, you need to have a B.Tech degree in the same stream. After B.Sc in Agriculture, you can pursue M.Sc in Agriculture. The reason why you cannot pursue M.Tech after B.Sc is because B.Sc is a Sceince degree and M.Tech is a Technology degree. And you cannot even apply for GATE after B.Sc.

Hello Monisha,
You are b.sc agriculture graduate so you can apply for m.sc agriculture but for M.tech you have to complete your graduation in B.tech then only you can apply for M.tech. B.sc graduate cannot elegible for M.tech. You cannot even apply for GATE to get the admission in M.tech. But you are elegible for M.sc agriculture so go for it.