Hey,

In every school pre boards are a mandatory thing to give before your boards. It is a kind of sample test to check your preparation before your actual board exams.. Some schools also have rules for student to pass in the board exam in order to get the Admit Card.

Yes the marks are given by the external. But it's no loss if you talk to the school authorities calmly and come up with a solution to cope  with problem.

All the very best for your Board exams.

Thank you.