As per my knowledge, in the first step of revarification itself, the recalculation of marks is done, then how is it possible that there remains a discrepancy. It must have already been rectified by now. Or if the procedure was dfferent this year, let me know about it in the comment section.

So, in case the problem you have told is correct, you need to ask yourself if you are very confident that you should have scored more. And yes, after reevaluation, marks do increase, you may get more marks, but definitely you will lose those 5 marks in case they have been incorrectly added. You may show your answersheet copy to an experienced teacher of your school or coaching. He/she can guide you aout the answers and their correctness. The quality and content of answers, proper diagrams, clarity and presentation of answers are the factors of evaluation of answers. So, go for it only if you are really sure about it and do tell me about the recalculation step, if it was there or not.

Hope this helps. All the best.