21. Limitation. (1) A Tribunal shall not admit an application,-- (a) in a case where a final order such as is mentioned in clause (a) of sub-section (2) of section 20 has been made in connection with the grievance unless the application is made, within one year from the date on which such final order has been made; (b) in a case where an appeal or representation such as is mentioned in clause (b) of sub-section (2) of section 20 has been made and a period of six months had expired thereafter without such final order having been made, within one year from the date of expiry of the said period of six months. (2) Notwithstanding anything contained in sub-section (1), where- - (a) the grievance in respect of which an application is made had arisen by reason of any order made at any time during the period of three years immediately preceding the date on which the jurisdiction, powers and authority of the Tribunal becomes exercisable under this Act in respect of the matter to which such order relates; and (b) no proceedings for the redressal of such grievance had been commenced before the said date before any High Court, the application shall be entertained by the Tribunal if it is made within the period referred to in clause (a), or, as the case may be, clause (b), of sub-section (1) or within a period of six months from the said date, whichever period expires later. (3) Notwithstanding anything contained in sub-section (1) or sub- section (2), an application may be admitted after the period of one year specified in clause (a) or clause (b) of sub-section (1) or, as the case 58 may be, the period of six months specified in sub-section (2), if the applicant satisfies the Tribunal that he had sufficient cause for not making the application within such period.