Hey Nisha! You are definitely eligible for Agricultural Entrance 2020 in BHU. The entrance has nothing to do with what you where into before, if you are fulfilling the age  criteria which you are then you are good to go. So don't worry about it much just prepare for the entrance. Hope this may help you. 

Hello Nisha.

Yes surely you are eligible for Bsc UG agriculture entance 2020. It doesn't have to do anything as you are still fulfilling age criteria . And one more thing once you already completed your Bsc i.e. UG so why again going for UG . You can now apply for Msc also.

All the best.