Authority definition updated to encompass bodies constituted or authorised under the Customs Act for advance rulings. Amendment substitutes clause (e) of section 23A of the Central Excise Act to define Authority as the body constituted under subsection (1) or authorised under subsection (2A) of section 28F of the Customs Act, thereby aligning the Act's reference to the Advance Rulings mechanism with entities established or authorised under the Customs Act.