Authorisation of central tax officers as proper officers enables coordinated orders and bars duplicate proceedings on the same subject matter. Section 6 authorises officers appointed under the Central Goods and Services Tax Act to serve as proper officers under the Mizoram Goods and Services Tax Act subject to notification-specified conditions; requires that orders under this Act be accompanied by corresponding orders under the Central Act with intimation to the jurisdictional central tax officer; bars initiation of duplicate proceedings where the central proper officer has already acted on the same subject matter; and precludes rectification, appeal and revision of orders under this Act before officers appointed under the Central GST Act.