(7)Every application made before the Appellate Tribunal,(a)in an appeal 325[* * *] for rectification of mistake or for any other purpose; or(b)for restoration of an appeal or an application,shall be accompanied by a fee of five hundred rupees:Provided that no such fee shall be payable in the case of an application filed by or on behalf of the 326[Principal Commissioner of Central Excise or Commissioner of Central Excise] under this sub-section.]