Explanation:

RBI has the sole right to issue bank notes and this provision is given in section 22 of the RBI act.

22. Right to issue bank notes.
(1) The Bank shall have the sole right to issue bank notes in India, and may, for a period which shall be fixed by the Central Government on the recommendation of the Central Board, issue currency notes of the Government of India supplied to it by the 4[Central Government], and the provisions of this Act applicable to bank notes shall, unless a contrary intention appears, apply to all currency notes of the Government of India issued either by the Central Government or by the Bank in like manner as if such currency notes were bank notes, and references in this Act to bank notes shall be construed accordingly.
(2) On and from the date on which this Chapter comes into force the Central Government shall not issue any currency notes.