Hi Gagan,

For which board you are asking, Central Board of Secondary Education(CBSE) or any state board. If your question is not regarding any specific  board and you are asking generally, then, every school having 10th or 12th class or even 8th in some states are affiliated to one or the other board. It is compulsory for a school to take affiliation from any recognised board.

Feel free to ask doubts in the Comment Section.

I hope this information helps you.

Good Luck!