I Under the Income-tax act, every person, who is an assessee and whose total income exceeds the maximum exemption limit, shall be chargeable to the income tax at the rate or rates prescribed in the finance act. Such income tax shall be paid on the total income of the previous year in the relevant assessment year . But the total income of an individual is determined on the basis of his residential status in India .

Resident and Non Residents :
The income tax to be paid by an individual is determined by his residential status. An individual can be termed as a 'resident' if he stays for the prescribed period during a fiscal year i.e. 1st April to 31st March either for--

29 182 days or more, or

30 60 days or more (182 days or more for NRIs) and has been in India in aggregate for 365 days or more in the previous four years.

Any perosn who does not satisfy these norms is termed as a 'non-resident'.