Rectification of advance ruling: authority may amend orders to correct apparent errors, hearing required if liability increases. The authority or the Appellate Authority may amend any advance ruling order to rectify errors apparent on the face of the record, on its own motion or when brought to its notice by an officer, the jurisdictional officer, the applicant or the appellant, subject to a time limitation; provided that no amendment that increases tax liability or reduces admissible input tax credit shall be made unless the applicant or appellant is given an opportunity of being heard.