Any person aggrieved by an order of the Board refusing to grant a certificate or revoking a certificate may, in such manner and within such period as may be prescribed, prefer an appeal to the State Government or to such authority as may be specified by it against such refusal or revocation:
     Provided that the State Government or the authority so specified, as the case may be, may admit an appeal after the expiry of the period so prescribed, if it is satisfied that the applicant was prevented by sufficient cause from preferring the appeal in time.