Section 6(4) in The High Denomination Bank Notes (Demonetisation) Act, 1978
(4)Notwithstanding anything contained in sub- sections (1), (2) and (3), where the return referred to in section 5 is presented in the manner provided in the proviso to sub- section (3) of that section, the exchange referred to in this section may be effected only by the Reserve Bank at Bombay.
