A person residing outside India who is a citizen of India or a person outside India who is of Indian origin is an NRI. The definition of Person resident outside India is defined under section 2(w) of Foreign Exchange Management Act, 1999 as "a person who is not resident in India"
A person shall be deemed to be a person not resident in India in the following cases:-
When the person stays in India for less than or up to 182 days during the preceding financial year
When a person who has gone out of India or who stays outside India, in either case -
a) for or on taking up employment outside India, or
b) for carrying on outside India a business or vocation outside India, or
c) for any other purpose, in such circumstances as would indicate his intention to stay outside India for an uncertain period