The instructions state that there is no correction window for SSC CHSL application form. The form must be filled correct so as to avoid any rejections. The instructions state that if at any point in time, it is found that Candidates have entered wrong information, the candidature is likely to be cancelled. In your case, though the rest of the application form is correct, if the year of passing has been entered wrong, the chances of the candidature being cancelled are high after document verification because if selected, this might determine your seniority during promotions.So what we would suggest you to do is to register afresh using a new email id or mobile number and then fill in the application form again. The application fee is nominal and is Rs. 100 and so it is financially feasible too. It is better to fill a new application than losing a candidature for a small error. Please read our article for more information as how to fill in the application form: https://competition.careers360.com/articles/ssc-chsl-application-form