Central Board Of Secondary Education [CBSE] — I'm complaining about low marks in theory

This is to inform you that my son Venu Gopal Singh is a student of class 12th SCIENCE, appeared in the Board Examination with Roll no.[protected] in this pandemic year.
As per the results declared on 30.07.2021 from CBSE Board, I found his performance quiet disappointing. He got 57% in 12th specially in maths and chemistry (21 marks in maths and 25 marks in chemistry).
According to the guidelines given to school by the CBSE Board for the evaluation of numbers of the appeared students for theory was 30% from class 10th, 30% in class 11th and 40% from class 12th examination.
Keeping view of the above facts, I found mismatch in my son's results for theoretical subject.
So, I am requesting you to review the numbers and take appropriate step to evaluate my son's result again.

Thanking you