Dear Shahid Mansoori,

You can write the letter as follows:-

Respected VC Sir,

Subject:- Regarding attendence in Mark Sheet

I'm student of your college(mention roll number. Or registration number if any). Please recheck the Mark sheet. I have been marked absent in the mark sheet. But i was present that time. Kindly do check it.

I shall be very thankful to you.

Yours obediently,

Your name, class, roll number here

Hope this sorted your query.

All the Best!!