How to determine the reversals of credit in case of special circumstances i.e. change of the scheme from Composition to Regular scheme, supplies becoming taxable which were earlier exempt and cancellation of registration

In terms of Rule 44(1) (a) of the CGST Rules, 2017, the reversal of input tax credit relating to inputs lying in stock will be calculated proportionately on the basis of corresponding invoices on which credit had been availed. Further, in terms of Rule 44(1)(b) of the CGST Rules, 2017, for capital goods, the input tax credit relating to the remaining residual life in months shall be computed on pro-rata basis, taking the useful life as five years.(Part of the month shall be ignored while calculation).

(ICAI FAQ PUBLICATIONS 06-09-2017 INPUT TAX CREDIT: FAQ NO. 61)