Section 42(3)(b) in The Central Goods and Services Tax Rules, 2017
(b)where the aggregate of the amounts determined under sub-rule (1) in respect of 'D1' and 'D2' exceeds the aggregate of the amounts calculated finally in respect of 'D1' and 'D2', such excess amount shall be claimed as credit by the registered person in his return for a month not later than the month of September following the end of the financial year in which the completion certificate is issued or first occupation takes place of the project.