Rectification of advance ruling allows amendment for errors apparent on record, subject to hearing before increasing tax liability. The Authority or the Appellate Authority may amend an order under the advance ruling provisions to rectify any error apparent on the face of the record, whether noticed suo motu or brought to notice by the concerned officer, jurisdictional officer, applicant or appellant, provided this occurs within the statutory time limit; no rectification that would increase tax liability or reduce admissible input tax credit shall be made without giving the applicant or appellant an opportunity of being heard.