Central Board Of Secondary Education [CBSE] — Regarding getting low marks in the result

Yesterday on 3rd August I got my result . I was excepting 90+% but I got 88% only .I approached my principal he said you are a brilliant student we gave you good marks then I want to know from board that on what basis result is made .The students who were always last in class get 80+% but toppers get below 70%.Board is saying to give a exam if we are unsatisfied you can give exam I am asking that how a student who has paused his study from 5 months can prepare for exam in 1-2 months .It is just not a messing with our future .I request the board to recheck result of of mine . It is a humble request of a student to the board.
Thankyou!
Aadiy Khan
Class-10th
roll no[protected]
school no-81364