(4A)Sub-section (1) or sub-section (2) or sub-section (3) or sub-section (3A) shall not apply in relation to any income of a trust or an institution, being profits and gains of business, unless the business is incidental to the attainment of the objectives of the trust or, as the case may be, institution, and separate books of account are maintained by such trust or institution in respect of such business.
