(6)Every person who, immediately before the issue of a notification under sub-section (1), was serving in a Municipality on any post in relation to which a Municipal Service is constituted under sub-section (1), shall, on the issue of such notification, become a member of the corresponding Municipal Service constituted under sub-section (1):Provided that the terms and conditions of service of a person who becomes a member of the Municipal Service in the manner referred to in this sub-section, in so far as they relate to remuneration, gratuity and provident fund, shall not be varied to his disadvantage on his becoming a member of the Municipal Service.