Yes, Explanation to Section 44 of MGL has such a provision. It provides that where goods received as an inward supply is returned by the recipient to the supplier within six months from the date of the relevant invoice, the tax payable on such supplies shall be equal to the input tax credit availed earlier on such inward supply. This provision essentially ensures that if the recipient returns the goods to the supplier within six months of the date of its original supply, his tax liability on such returned goods will be the same as was at the time of the original supply. If goods are returned after six months of the date of the original supply invoice, the rate of tax applicable will be the rate prevailing on date of such return.