Same Input credit taken twice

A person wrongly taken same input twice in different month. After few months he noticed that error. So how he rectify now,  For example, Rs. 5000 was actually input which he was taken in the month of March,19. Again same input he was taken in the next month in the month of April'19, he already filed May, june and july, aug, sep, oct. how he adjust this input in the month of nov'19 in the return.  how he will shown in 3B. please help.