Hi,

between BSc agriculture and BSc biotechnology I would suggest you to go for MSc biotechnology.

India houses a very good amount of institutes for BSc biotechnology you need to do post graduation and probably if you are interested in research and development then a PhD

if you are interested in the teaching field then you can also go for professor posts and Institute faculty post which are also given out by Indian government under some entrance and qualifying exams in many institutes within India.

All in all the field Biotechnology very good and improving scope in India right now as compared to agriculture.

You can got decant job after completing bsc Agriculture and you can do MSc for improve your chances and do PhD to become scientist/assistant professor or professor in research institutions and universities.