Section 9. The operating agencies having the powers and subject to the limitations provided in sections forty-five to fifty-seven, inclusive, to be known as urban renewal agencies, shall be:—
(a) each redevelopment authority;
(b) each housing authority of a city or town in which no redevelopment authority has been organized; provided, however, that no housing authority shall initiate an urban renewal project until the municipal officers of a city or an annual or special town meeting shall have determined that there exists in such city or town a need for urban renewal;
(c) each housing authority of a city or town in which a redevelopment authority has been organized, but only with respect to projects initiated by such authority before the organization of a redevelopment authority and subject to section fifty-one.