Dear Student ,

yes , you can apply for Duplicate certificate by mentioning proper reason of losing the certificate in the application form that you need to submit in the board office or you school , in some cases .. you may need to do an FIR in Police Station to submit a copy of that to the board .

Also,  carry /attach the admit card of the exam that you have appeared (12th) which will prove that you've registered for the exam ..

hope this helps !