set off of business loss

Please clarify whether late return was for last year in which loss is incurred

or late return is for current year in which loss is to be set off

considering both situation e.g.

FY 2016-17 = loss is 20,000 (filed within due date)

FY 2017-18 = Profit is 100,000 (filed Late, not within due date)

Then loss of FY 2016-17 of Rs. 20,000/- can be set off against profit of Rs. 100,000/-and balance taxable profit Rs. 80,000/-

If return for FY 2016-17 is filed not within due date then loss can not be set off