(3)Every appeal under this section shall be preferred within a period of thirty days from the date of order of a District Commission or a State Commission or the National Commission, as the case may be:Provided that the State Commission or the National Commission or the Supreme Court, as the case may be, may entertain an appeal after the expiry of the said period of thirty days, if it is satisfied that the appellant had sufficient cause for not preferring the appeal within the said period of thirty days.
