9. The Government may, by rule or order publish in the official Gazette,- (a) reduce or remit, whether prospectively or retrospectively, in the whole or any part of the territories under its administration, the duties with which any instruments, or any particular class of instruments, or any of the instruments belonging to such class, or any instruments when executed by or in favour of any particular class of persons, or by or in favour of any members of such class, are chargeable, and (b) provide for the composition or consolidation of duties in the case of issues by any incorporated company or other body corporate of debentures, bonds or other marketable securities.