Would GST be payable on goods not intended to be sold, taken out for participation in overseas exhibitions and trade fairs and brought back into India as these goods are meant for exhibition only

GST is not payable in such cases. Exporters will need exhibition participation letter and no foreign exchange involved letter from the concerned bank for the purpose of exchange control requirements. At the time of re-import, identity of goods imported with export goods needs to be established to seek
exemption from import duty in accordance with Customs provisions. IGST will be exempted at the time of re-import in view of exemptions granted under Customs.

(FAQ 16: HANDICRAFTS)