Orders constituting Appellate Tribunal to be final and not to invalidate its proceedings

Orders constituting Appellate Tribunal to be final and not to invalidate its proceedings.–No order of the Central Government appointing any person as the [Chairperson or the Member] of a [Appellate Tribunal] shall be called in question in any manner and no act or proceeding before a [Appellate Tribunal] shall be called in question in any manner on the ground merely of any defect in the constitution of a [Appellate Tribunal].