HI , 

Kindly tell us for which exam have you applied.! Usually in most of the exams after correction date is completed you can not correct it. But there is one option available, Go to the official wenbsite of the exam portal and go through contact us. there you would find an email id and a phone number to contact the officials working for that board . Mail them regarding this issue. You should get response from them within 24 hours. If you havent got any response , then call to the given number and talk to the officials. You might be able to resolve this issue. 

Good Luck, Hope it was of help. :)