Hello

It depends on your school. Generally, students of CBSE board are required to have 75% attendance in Class 12th. Medical certificates are also accepted by schools in genuine cases. 
You should contact your teachers regarding the attendance matter.

Good Luck!

Hii Chandraprakash Maurya..

Mostly they won't allow. Talk with your seniors they will suggest you how to bypass that if possible with some tactics they know better.

If you want to talk with the institute itself that here are the details

• Email – sitpithoragarh@gmail.com
• Contact No.- 05964-264060

Hope this helps you. All the best.