Residence in India determines tax scope; criteria include physical presence, place of effective management, and high income domicile test. Section 6 establishes tests for being resident in India: for individuals, residence is primarily determined by prescribed physical presence thresholds, with explanatory provisos modifying day counts for Indian citizens who leave for employment or visit from abroad and a deeming rule making certain high income citizens residents if not taxable elsewhere; HUFs, firms and associations are resident unless control and management is wholly outside India; a company is resident if Indian or if its place of effective management is in India.