Set off & carry forward of losses

Also tel me the relevant section. Is it section 79 of IT act 1961 ?

Yes the company can set off the loss incurred in AY 2012-12  with the profit of the AY 2014-15 provided the company has filed the income tax return before the due date.

The relevant section is section 79 of the Income Tax Act, 1961.
 

No, the company cannot setoff of the AY 2012-13 Loss in AY 2014-15. It is mandatoy to set off loss in the AY 2013-14.

It is mandatory to set off loss in the AY 2013-14.

It is mandatory to set off the carried forward losses in the immediately succeeding year, against the income of such succeeding year. Otherwise, the losses will get lapsed. Tyresoles v CIT 49 ITR 515 (Madras).

So, Revise return of AY 2013-14 and get refund of tax paid in AY 2013-14