Hello, i understand your situation and think it is a very reasonable thought. However, your 10th and 12th standard's exams are not the only requisites for getting a job after your graduation. Other factors like ;  your college's placement records, your Semester marks, work experience,  co- curricular activities, etc.

You cannot change your +2 marksheet but can surely work on building your CV for increasing your chances of getting placed or getting a good job.

ALL THE BEST !