Section 60(8)(i) in The Central Goods and Services Tax Rules, 2017
(i)for the first and second month of a quarter, a day after the due date of furnishing of details of outward supplies for the said month, in the IFF by a registered person required to furnish return for every quarter under proviso to sub-section (1) of section 39, or in FORM GSTR-1 by a registered person, other than those required to furnish return for every quarter under proviso to sub-section (1) of section 39, whichever is later;