There are many colleges available so it would be better if you could tell which paticular state you are interested in but generally below mentioned colleges are considered to be decent -

INDIAN AGRICULTURAL RESEARCH INSTITUTE - [IARI], NEW DELHI

TAMIL NADU AGRICULTURAL UNIVERSITY - [TNAU], COIMBATORE

ACHARYA NG RANGA AGRICULTURAL UNIVERSITY - [ANGRAU], HYDERABAD

JAWAHARLAL NEHRU UNIVERSITY - [JNU], NEW DELHI

PUNJAB AGRICULTURAL UNIVERSITY - [PAU], LUDHIANA

GOVIND BALLABH PANT UNIVERSITY OF AGRICULTURE AND TECHNOLOGY, PANTNAGAR

UNIVERSITY OF CALCUTTA, KOLKATA

COCHIN UNIVERSITY OF SCIENCE AND TECHNOLOGY - [CUSAT], KOCHI etc.

Good Luck!!!