I have a spelling mistake in my 10th and 12th cbse certificates.I am not indian.I studied in an indian school abroad.I would like to know the procedure and the time required to get the new cbse certificate?

You will have to consult with the college or uni where you took your certifications. We cannot answer this question for you, we have no access to this information.

You will have to contact the school to see if they will and the cost to reissue, if there is any issue it may take a while.