Though India does not recognize dual citizenship, in 2006 the government launched the Overseas Citizens of India (OCI) program. It extends to qualifying individuals limited travel and residency privileges and is one of many types of travel visas offered by the Indian Government.
Also, if you previously held Indian citizenship and have since become a U.S. citizen, your Indian passport is no longer valid and will not be accepted by customs agents. If Indian immigration authorities find persons of Indian origin entering India in possession of non‐cancelled Indian passports, they will seize such passports. All foreign nationals, however, must present a valid passport and a visa when traveling to India. This is regardless if they hold an Overseas Citizens of India (OCI) card.
It is important to obtain the appropriate travel visa prior to arriving in India, as U.S. citizens cannot obtain one after arrival. To be safe, carry photocopies of the bio‐data page of your U.S. passport as well as the pages containing the Indian visa and immigration stamps in the event that your passport is lost or stolen.