Articles 5 to 11 in Part-II of the Constitution deals with citizenship and it defines a citizen as an individual of Indian domicile or someone with an Indian lineage within the family. Article 10 deals with the continuance of foreigners as Indian citizens, subject to any laws enacted thereafter by the legislature. The Indian constitution only recognizes single citizenship throughout the country and doesn’t support dual citizenship. It also declares that a far off citizen can acquire Indian citizenship through the method of Naturalization (ordinarily residing in India for 14 years) and registration of foreigners with the FRRO (Foreigners Regional Registration Officer) or FRO (Foreigners Registration Officer). The Indian law follows legal principle (citizenship by blood) as against legal principle (citizenship by birth).

Bureau of Immigration (BoI) was setup in 1971 by Government of India to undertake Immigration function within the country. BoI is headed by Commissioner of Immigration and assisted by FRROs for immigration facilitation service at airports and work concerning registration of foreigners under various Acts and Rules. Altogether, there are 86 Immigration Check Posts everywhere India, catering to international traffic. Out of those, 37 ICPs are functioning under the BoI, while the remaining are being managed by the concerned State Governments. at the present, there are 12 FRROs in major cities i.e. Delhi, Mumbai Kolkata, Chennai, Amritsar, Bengaluru, Hyderabad, Calicut, Kochi, Trivandrum, Lucknow and Ahmedabad. aside from this, there are 12 Chief Immigration Officers within the cities i.e. Goa, Jaipur, Gaya, Varanasi, Nagpur, Pune, Mangalore, Trichy, Coimbatore, Bagdogra, Chandigarh and Guwahati. At remaining places District Superintendent of Police (SP) or the prescribed authority functions as FRO to facilitate foreigners.