Dear candidate.........

Well, only 12th marksheet and pass certificate issued by a state board or CBSE are required for getting admission into an engineering or medical or any other college. But some colleges may also demand for both 11th and 12th board certificates at the time of admission, which you cannot deny at any cost. Also for getting a valid 12th certificate, you must pass 11 standard and must also possess 11th passing certificate. But still if you can manage, then there may not be any discrepancy at the time of admission.

Hope this helps you out.....

Best of luck!!