Hi student,

If it asks you the board of school from which you did your class 10th, then you should enter the board that your school followed when you were in class 10th( example CBSE or ICSE etc.). Same goes for class 12th, if it asks you for information on your class 12th school, you should enter the board that your school followed when you were in class 12th

Hope it helps.

Good luck.