Section 18(8)(i) in U.P. Inter-State Migrant Workmen (Regulation of Employment and Conditions of Service) Rules, 1983
(i)Where an appeal has been dismissed under sub-rule (7), the appellant may apply to the Appellate Officer for readmission of the appeal, and where it is proved that he-was prevented by any sufficient cause from appearing when appeal was called on for hearing, the Appellate Officer shall restore the appeal to its original number.