Sale of old gold jewellery will not attract GST on exchange. However, if an unregd. supplier of gold ornaments sells it to a regd. supplier the tax will apply under RCM
It is not a notified Case u/s 9(3) of the CGST Act 2017. And also Section 9(4) of the CGST Act 2017 is now applicable only from purchase from Notified Person of Notified Goods. Gold is still not notified. Hence RCM not applicable.