There is no "Visa Regime" between India and Bhutan and hence Bhutanese nationals visiting India or Indian Nationals visiting Bhutan do not require any Visa to visit each other's country.
However, in exceptional circumstances, Embassy of India, Thimphu, Bhutan, grants visas to third country foreigners intending to visit India for tourist, transit and other purposes, in accordance with the rules and regulations governing Visa issues.
Non-resident foreigners must acquire Indian visa from his/her country or from the country of his/her residence. A non-resident foreigner applying for visa at Embassy of India, Thimphu shall be required to appear in person for obtaining visa and should explain why the individual did not obtain a visa from Embassy /Consulate of India in his own country. In these cases a minimum of four working days are required for processing visa.
An applicant should fill in the Visa Form duly signed along with the TELEX Form, and submit two recent passport size photographs, copy of Bhutan Visa, air tickets, etc. All entries in the Visa Application form must be filled-in correctly by the applicant. Forms with missing or incorrect entries would be summarily rejected.
Foreigners in Bhutan intending to visit India for Tourism purpose should fill in the Visa Form along with the request for the period of visa and indicating the places where he/she intends to visit.
2. Transit Visa
The Visa application must accompany the copies of confirmed air tickets (from Bhutan to India; and/or India to abroad). Transit Visa is valid for a maximum period of 72 hours (3 days) stay in India during the specified period. If transit is by surface/land route, the applicant must indicate the place of entry and the place of exit with dates and also the mode of transport. If the journey is to be performed by train in India, then the copy of confirmed train ticket must be enclosed with the application.