The revaluation consists of three steps.
- Reverification Request :- This is the first step of revaluation process. A request is submitted in which CBSE checks for calculation mistake, non evaluated questions etc. They charge Rs. 500 for this and is the most non-trustworthy step.
- Answer sheet Request :- In this you are allowed to see scanned images of your answer sheet. This is quite important one, so if you have got confidence that you did well, then definitely go till this step. Charges are around Rs. 700.They will be sent by the post by 19th june 2018
- Revaluation of questions :- This is the last one in which a specified number of questions are checked again.
But the chances are very rare, if the error is not quite sufficient enough. Also, if the examiner finds that more than deserved marks are given, they have got the right to deduct marks as well. So, subjects like languages and other writing focused ones should have a great confidence to support the cause.
A increase of 11 marks in mathematics is quite rare, but you may go ahead as it may affect your future.
So, all depends upon whether you have got the confidence that you performed well.
All the best. May the best happens.