No notification under sub-section (3) of section 1 shall be made in respect of Part III of this Chapter, unless, in the area to which such part is applied, rent-rates have been determined and the record-of-rights has been framed in accordance with the provisions of this Chapter:
     Provided that if the Chief Commissioner is satisfied that in such area the rent-rates determined in the year of settlement and the record-of-rights framed in such year and maintained since are reliable, he may accept such rent-rates, with or without modification, and such record-of-rights, as framed and determined in accordance with the provisions of this Chapter.