28 March 2018
revised return can be filed before the end of one year from the end of the relevant assessment year or before the completion of the assessment, whichever is earlier. In other words, for FY 2015-16, the deadline is March 31, 2018, and for FY 2016-17, it is March 31, 2019. if return filed after the due date (belated return). For FY 2015-16, a belated return cannot be revised. But for FY 2016-17, a belated return can be revised at any time before March 31, 2019.