non-resident Indian (NRI) is an Indian citizen who has migrated to another country, a person of Indian origin who is born outside India, or a person of Indian origin who resides outside India. Other terms with the same meaning are overseas Indian and expatriate Indian. In common usage, this often includes Indian-born individuals (and also people of other nations with Indian blood) who have taken the citizenship of other countries

Persons who were citizen of certain specified countries; or whose spouse; or either of whose parents, grandparents, great-grandparents were citizens at any time of these specified countries may render an applicant ineligible for a PIO card even though he/she may otherwise be eligible. The grounds of ineligibility can be established only after receipt of application. It will not be possible to respond to queries regarding grounds of ineligibility before receiving the application.

Based on the recommendation of the High Level committee on Indian Diaspora, the Government of India decided to accord Overseas Citizenship of India (OCI). OCI scheme is operational from December 2, 2005.

Persons registered as OCI have not been given any voting/political rights. The Constitution of India does not allow holding Indian citizenship and citizenship of a foreign country simultaneously.