Section 5A. The department shall promulgate regulations establishing election procedures for tenants to elect a tenant as a member of the housing authority in the town and regulations establishing appointment by the board of selectmen of the town, if no election may be held; provided, however, that 1 member of the housing authority board shall be a tenant. The department shall provide regulations creating waiver of this section if federal law requires the town to maintain a tenant member as 1 of the 5 members or if a tenant has been elected under section 5.