Section 39(1)(i) in The Central Goods and Services Tax Rules, 2017
(i)any additional amount of input tax credit on account of issuance of a debit note to an Input Service Distributor by the supplier shall be distributed in the manner and subject to the conditions specified in clauses (a) to (f) and the amount attributable to any recipient shall be calculated in the manner provided in clause (d) and such credit shall be distributed in the month in which the debit note is included in the return in FORM GSTR-6;