Help required urgently

There is a trust which is not registered under Sec 12A. We applied for 12A registration. The A.O asked us to pay the tax for the previous years income received as there was no 12A. We have paid the taxes. Now while filing the return, my question is, which ITR Form should we fill it and file. Is it ITR-7 (Trust) or ITR-5 (AOP). The tax was paid as if it was an AOP. Please advice.