(6)Where the gross total income of an assessee––(a)consists only of the income referred to in sub-section (1) (Table: Sl. No. 1 to 7), no deduction shall be allowed under Chapter VIII and Schedule XV;(b)includes any income referred to in sub-section (1) (Table: Sl. No. 1 to 7), the gross total income shall be reduced by such income and the deduction under Chapter VIII shall be allowed as if such reduced amount were the gross total income of the assessee.