Revision of returns: recoveries treated as arrears under GST and ineligible for input tax credit; timely refunds follow earlier law. Revisions of returns filed under the earlier law produce two outcomes: if a post-appointed-day revision shows amounts recoverable or credits inadmissible, those amounts are recovered as an arrear of tax under GST and are not admissible as input tax credit; if the revision occurs after the appointed day but within the earlier law's revision time limit and shows refundable amounts or admissible cenvat/input tax credit, the refund or credit shall be effected under the earlier law in accordance with its provisions.