Section 64(1)(a) in The Gujarat Municipalities Act, 1963
(a)join with any other municipality, cantonment authority, panchayat or committee appointed for a notified area or with any combination of such municipalities, authorities, panchayats or committees.(i)in appointing out of their respective bodies a joint committee for any purpose in which they are jointly interested, and in appointing a chairman of such committee; and(ii)in delegating to any such committee power to frame terms binding on each such body as to the construction and future maintenance of any joint work, and any power which might be exercised by any of such bodies, and(iii)in framing and modifying rules for regulating the proceedings of any such committee in respect of the purpose for which the committee is appointed, and