People who lose their passport with their valid Indian visa must contact their respective country's Embassy for their new replacement passport and apply for an exit visa with the
Foreigner's Regional Registration Office (FRRO), Government of India.
This process takes up to 2-3 business days. You cannot leave India
without this visa. More information on obtaining an exit visa will be
provided when you come to apply for a replacement passport. Exit visas
are not issued on weekends or Indian holidays.
If you are planning to travel to India and avail its Visa-on-arrival facility, then you must know that you need pre-authorization of visa prior to your travel to India.
General thought is that the Indian visa is granted on arrival but this is a wrong presumption.
The Indian consulate to which you shall apply for visa depends on the State you live in. Other than Indian Embassy there are 4 Indian consulates and they all have their own state jurisdictions.