According to the Foreign Exchange Regulation Act of 1973, Non-Resident Indians are:

1. Indian citizens who stay abroad for employment or carrying on business or vocation outside India or for any other purpose in circumstances indicating an indefinite period of stay abroad; OR
2. Government servants who are posted abroad on duty with the Indian missions and similar other agencies set up abroad by the Government of India where the officials draw their salaries out of Government resources; OR
3. Government servants deputed abroad on assignments with foreign Governments or regional/international agencies like the World Bank, United Nations etc.  OR 
4. Officials of the State Government and Public Sector Undertakings deputed abroad on temporary assignments or posted to their branches or offices abroad.

Foreign direct investments by NRIs up to 100% is allowed, and full repatriation is allowed without prior approval, except when the investment is

• made in the manufacture of products reserved for the public sector, or industries that need a compulsory license, or proposed to be located at a restricted site
• in real estate, civil aviation and housing
• in excess of specified sectoral caps
• more than 24 percent in units manufacturing products reserved for small scale industries, or companies registered as small scale units
• in/for a 2nd tie-up with another company in India
• to purchase shares of an existing shareholder of an Indian company.
  
  

This is the automatic route of the RBI. NRIs can invest in Export Oriented Units, Free Trade Zones or Export Processing Zones, Software technology Parks, Electronic Hardware Technology Parks and Special Economic Zones.

In the case of investments listed in the above excepted categories, prior government approval from the Secretariat for Industrial Assistance/ Foreign Investment Promotion Boards of the Government of India is required, and full repatriation is allowed.

Acquisition /Selling/Transfer of Property in India by an Indian citizen resident outside India
A person resident outside India, but is still a citizen of India, can

• acquire any residential or commercial property in India
• transfer any immovable property to a person resident in India
• transfer any immovable property other than agricultural/plantation property/farmhouse to a person resident outside India or to a person of Indian origin resident outside India

• A PIO can acquire immovable property as a gift or an inheritance from an Indian resident or an NRI or a PIO
• A PIO can acquire immovable property from a PIO who had acquired the property from a resident Indian who had, in turn, acquired it as per the foreign exchange laws prevailing at the time.
• A PIO can sell property to a resident Indian, including agricultural and farmland property
• A PIO can gift residential or commercial property to a resident Indian or to NRI or a PIO

On conclusion of sale of immovable property other than agricultural land / farm house/plantation property in India by either an NRI or PIO, the person can remit the funds provided all the conditions noted below are met:

• All the provisions of the Exchange Control Rules/Regulations/Law in force at the time were met at the time of acquisition, or the provisions of the Regulations framed under the Foreign Exchange Management Act, 1999; 
• NRIs/PIOs can remit sale proceeds of immovable property irrespective of how long the property was held. The profits from the sale of such property cannot be repatriated. The repatriation should not be more than the amount remitted to acquire the said property.