dear rajesh .
no , class 12th board is not the only criteria by which jee verify the candidate , you have to give aadhar card details also , and you cannot give the same aadhar card details twice .
and also , in other case , your candidature may be cancelled by jee .
so, 1 case will be possible – you can give jee main 2017 with cbse board , then in 2018 , you can fill offline with bihar board . no other case are possible here .
HOPE IT HELPS
kindly approve
