If you have filed an incorrect tax return, you can correct it by filing a revised return as per the current tax laws. The Income Tax Act allows taxpayers to file a revised return under section 139(5). If you come to know something wrong statement in your original return, a revised return can be filed before three months prior to the end of the assessment year or before the end of the assessment, whichever is earlier. Moreover, The assessment year comes immediately after the financial year in which the ITR is filed.