(6)Where any committee is constituted under this section the members of the committee shall elect from amongst themselves the Chairman of the committee:Provided that-(a)Where the President and Vice-President both are members of any such committee, the President shall be the ex-officio chairman of such committee and if he declines to hold the office, the Vice-President shall be the ex-officio Chairman of the Committee, unless he also declines to hold the office,(b)where only one of them is a member thereof he shall be the ex-officio Chairman of the committee, unless he declines to hold the office and(c)a person who is not a member of the panchayat shall not be eligible to be the Chairman of any committee.