Done a mistake while filling up the application form

Dear sir, I had filled a form of ssc in 2015 under OBC category. There was column in the form for age relaxation claimed or not. By mistke i had opted No instaed of Yes.But my date of birth is already mentioned in that application form. It is already clear that i need age relaxation. As i was overage so i should had opted yes. Extra 3 years is permissible for OBC students. However my application was accepted and after exam result my name is in final merit list. Before final merit list there was a document verification process in which verifierer had to fill all the information in an online sheet. When he entered my dob in computer he relaxed my age under OBC (as i was over age) category and found me eligible under obc category. Means my details was corrected automatically in document verification process. He then take a print out of that copy and took my signature on that. Now scrutiny process is going on they will verify all my details again before appointment. Will that mistake create any problm for me? A single mistake which has been done unintentionally in the application form, can be cause of my rejection? If they reject my candidature can i fight legally with them? What are the chances for me to win this case?