Exclusion of dividend income from the taxable definition narrows the taxable base under the amended provision effective April 2004. The amendment substitutes the word 'income' in clause (a) of sub section (1) with 'income other than income by way of dividends referred to in section 115-O,' thereby excluding dividend receipts described in section 115-O from the income captured by clause (a); the substitution takes effect from 1 April 2004.