Notwithstanding anything contained in section 3, all suits, cases and other legal proceedings between the parties all of whom belong to the Scheduled Tribes specified in Item 2 of Part I—Assam, of the Schedule to the Constitution (Scheduled Tribes) Order, 1950, or such other tribe or tribes, as may be specified in this behalf, shall be tried and continue to be tried under the Assam Frontier (Administration of Justice) Regulation, 1945 (Regulation 1 of 1945) as if this Act had not been passed.