condonation of delay - writ jurisdiction

Sir, One of my service tax appeal ( 1st appeals ie. commissioner appeals) got dismissed based on the limitation period as there was 33 days delay where in the appellate authority has a power to condone the delay only to the extent of 30 days, but delay is 33 days, ie. more by 3 days, hence, dismissed. Now I am preffering the Writ Jurisdisdiction in the High Court. so, now my doubt is do I have to plead only with regard to condonation of delay or even the merits of the case also ?