The CBIC has issued the clarification in which it has been stated that the explanation having been inserted under section 11(3) of the CGST Act, is effective from the inception of the entry at Sl. No. 3(vi) of the notification No.
11/2017- CTR dated 28.06.2017, that is 21.09. 2017. The line in notification No. 17/2018-CTR dated 26.07.2018 which states that the notification shall come into effect from 27.07.2017 does not alter the operation of the notification in terms of Section 11(3) as explained in para 3 above.
To read the circular, click here circular-cgst-120