Rectification of mistakes- With a view to rectifying any mistake

apparent from record, the competent authority or the Appellate Tribunal, as the case may be, may amend any order made by it within a period of one year from the date of the order: Provided that if any such amendment is likely to affect any person prejudicially and the mistake is not of a clerical nature, it shall not be made without giving to such person a reasonable opportunity of being heard.