Hello, Anupam

Yes, It is valid. you are eligible for admission in engineering colleges and you can also appear in Central and State government jobs. Candidate passed 12th from a recognized board are eligible to appear in the entrance examination. Bihar Board of Open Schooling Examination is a recognized board.

Some private colleges do have a restriction for admission for BBOSE candidates, but it is a recognized board and is accepted for admission in most of the colleges.

Hope this is helpful, All the best!