Interest relief for delayed GST returns: nil-interest windows then a specified interest rate thereafter for eligible filers. Prescribes reduced interest for late GST payments filed in FORM GSTR-3B by two classes of registrants: those above the aggregate turnover threshold receive a brief nil-interest interval then interest until a cut-off date; those at or below the threshold with principal place in the State receive staggered nil-interest deadlines for February-July 2020, after which a uniform interest rate applies; the amendment is effective from the stated operative date.