(1)The members of the Public Service Commission for the Dominion of India holding office immediately before the commencement of this Constitution shall, unless they have elected otherwise, become on such commencement the members of the Public Service Commission for the Union and shall, notwithstanding anything in clauses (1) and (2) of article 316 but subject to the Proviso to clause (2) of that article, continue to hold office until the expiration of their term of office as determined under the rules which were applicable immediately before such commencement to such members.