Bihar Board of Open School Education is a recognised Board of the State Government of Bihar. So if you completed your 12th from BBOSE, it is valid across India. It is also valid in any University of Uttar Pradesh. Each State Government has a list of Boards that it recognises and Open School Boards of other States are recognised. UP Universities recognise Bihar Open School Board and so if you want to study BBA with your 12th from BBOSE, you can.