Advance tax liability triggers when income excluding capital gains exceeds prescribed thresholds, varying by assessee category and residency. The substituted section 208 makes advance tax payable during the financial year if total income excluding capital gains exceeds specified thresholds or if payable under other provisions; it sets distinct monetary thresholds for companies and local authorities, for registered firms, and two alternative thresholds for other persons depending on whether they were non-resident in the relevant previous year or not.