Nothing in section 7 shall authorise the making of any rules determing any agreement entered into by the Central Government with any person before the commencement of the Indian Telegraph (Amendment) Act, 1957 (47 of 1957), relating to the establishment, maintenance or working of any telegraph line, appliance or apparatus for telegraphic communication; and all rights and obligations thereunder relating to such establishment, maintenance or working shall be determined in accordance with the terms and conditions of such agreement.