If you have failed in three subjects in your 12th Science (GSEB) exam, you are eligible to appear for the supplementary exam .

Here’s what you need to do:

1. Supplementary Exam : GSEB provides an opportunity for students to clear their failed subjects through the supplementary exams. You will need to apply for the supplementary exams, which are usually held a few months after the regular exams.

2. Re-exam : In case you don’t clear the supplementary exams, you may have another chance to appear in the exams in the next academic year.

Make sure to check the official GSEB website or your school for updates regarding the dates and procedures for supplementary exams.

Hope this helps you!