Non-Resident Indian (NRI)
Who is a Non-Resident Indian
An Indian Citizen who stays abroad for employment/ carrying on business or vacation outside India or stays abroad under circumstances indicating an intention for an uncertain duration of stay abroad is a non-resident. (Persons posted in U.N. organizations and officials deputed abroad by Central/ State Government and Public Sector Undertakings on temporary assignments are also treated as non-resident) Non-resident foreign citizens of Indian Origin are treated on par with non-resident Indian citizens.
A. For the purpose of availing of the facilities of opening and maintenance of bank accounts and investments in shares/ securities in India:

A foreign citizen (other than a citizen of Pakistan or Bangladesh) is deemed to be of Indian Origin, if,
1. He, at any time, held an Indian passport.
2. He or either of his parents or any of his grand parents was a citizen of India bu virtue of the Constitution of India or Citizenship Act, 1956( 57 of 1955)
Note: A spouse ( not being a citizen of Pakistan or Bangladesh ) of an Indian Citizen or of a person of Indian Origin is also treated as a person of Indian origin for the above purpose.

B For Investment in immovable properties: A foreign citizen ( other than a citizen of Pakistan, Bangladesh, Afghanistan, Bhutan, Sri lanka or Nepal ), is deemed to be of Indian origin if,
1. He held an Indian passport at any time, OR
2. He or his father or paternal grand-father was a citizen of India by virtue of the Constitution of India or the Citizenship Act, 1955 ( 57 of 1955)