Haiii prabath!! As you are from the BSC agriculture, the best course I suggest you is MSc rather than ABM. And In MSc there are many other streams. By this you can also find many employment  opportunities in government  As well as in private sector like fertilizer manufacturing firms, Food processing industries,machinary industries plantations, colleges,agriculture products marketing firms.... And..Your future will be bright further. Hope I might have helped you a little bit to get off your confusion. All the best!!