Hello Pratham,
If you had failed in more than one subject ,then you cannot clear your 12th in the same year.You need to apply for 12th board again,if there are practical you have to clear those exams also.You can go for a private student,where one does not need to go school,you have to only go for writing your exams.You can sit at home and study . There is compartment exam,but that is only if you have failed one subject.Don't lose heart ,it happens with many students.Prepare this time well.
All the best
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