i have mistakenly enter my 12 th passed year. is there any problem

As per your previous query, it seems you are asking about SSC CHSL Examination. In the SSC CHSL application, candidates have to enter the passing years of both 10th, and 12th. But if you have entered the 12th passing year in a wrong place then it may create problem in later. Now if you have submitted your application then you can't modify it. But if you haven't submitted this, then you again login to your account and then edit the option. Or else, it is advisable to fill up another application with another mail Id to avoid any kind of hassle as the last date to fill the application has been extended till 19th December 2020. Check out this link http://news.careers360.com/ssc-chsl-notification-2020-21-released-sscnicin-check-dates-eligibility-application-details