For the purposes of section 335(e), gains of any commercial activity permissible under sections 344, 345 and 346, carried out by a registered non-profit organisation for a tax year, shall be computed in the following manner: —

(a) such commercial activity shall be treated as if it is entity separate from the registered non-profit organisation;

(b) separate books of accounts are maintained for such activities; and

(c) gains from such commercial activity during the tax year shall be computed as per the provisions of Part D of Chapter IV of the Act.