Taxable income calculation: subtract Chapter VI-A deductions from gross total income to determine tax liability under applicable regime. Gross Total Income is the aggregate of income from salary, house property, business or profession, capital gains and other sources; after adjusting inter-source and carried-forward losses as required, deductions under Chapter VI-A (commonly under sections 80C-80U) are subtracted from Gross Total Income to produce Total Income, which is the taxable income used to determine tax liability; electing a concessional tax regime requires computing Total Income without specified exemptions or deductions.