When to file the return ?????

Hi friends.....

1 of my client is a partnership firm..it has a net loss in its P&L....when should it file the return????

As it cannot declare 8% profit it cannot file return as per Sec 44AD before July 31st. Also, as per Sec 44AD only those assessees having taxable income which cannot declare 8% profit needs to be audited u/s 44AB. The firm does not have any other income and hence the taxable income is NIL. So when shud i file the return 

Somebody plzzzz help.....its urgent !!!!!