The Appellate Tribunal may amend any order passed by it under sub-section (1) so as to rectify any error apparent on the face of the record, if such error is noticed by it on its own accord, or is brought to its notice by the Commissioner or the Commissioner of State tax or the Commissioner of the Union territory tax or the other party to the appeal within a period of three months from the date of the order:
Provided that no amendment which has the effect of enhancing an assessment or reducing a refund or input tax credit or otherwise increasing the liability of the other party, shall be made under this sub-section, unless the party has been given an opportunity of being heard.