Yes, you can still file a belated tax return for FY 2015-16(AY 2016-17)The last date for filing the belated return for FY 2015-16 is 31st March 2018. Make sure that you do not make any mistake while filling the belated return because a belated return cannot be revised for FY 2015-16.
For FY 2016-17(AY 2017-18), the belated return can be filed on or before 31st March 2018.The belated return for FY 2016-17 can be revised.The last date for revising the return is also 31st March 2018.
If the return is not filed within the due date you will be liable to pay Interest u/s 234A
Read our guide on how to file income tax return online.