Registration under section 12AB required for trusts to secure exemption benefits, with prescribed application and audit timelines. The amendment requires trusts and institutions to obtain registration under the proposed section 12AB by filing an application to the Principal Commissioner or Commissioner within specified timelines-three months for formerly registered trusts, six months in advance for expiring or provisional registrations or inoperative registrations becoming operative, thirty days for non-conforming object modifications, and one month in other cases-and mandates that the accounts audit be completed and the audit report furnished by the specified date under section 44AB.