Hii,

If you are confident about your Answers and had a belief that marks gonna increase then Apply for Revaluation. They will recorrect your paper and Recount the marks. Marks may or may not increase. It depends on Your Answer sheet. But there is no guarantee that marks will increase. 

Dear Mani,

Usually marks increase or remain same in the case of revaluation but there have been cases where marks have been reduced. If you have faith that you did well in the exam and you expect aleast 10-12 marks more than your current score then only go for revaluation Otherwise 4-6 marks increase which is around a percent isn't worth the risk.