The Olympic torch arrived at New Delhi airport early on Thursday amid heavy security because of fears members of the world's largest community of exiled Tibetans may disrupt its passage through the Indian capital.
The torch, which is en route to China for the Summer Games in Beijing, was carried off a plane by Suresh Kalmadi, the chief of the Indian Olympic Association.
It was then taken along a route lined with hundreds of police to spend the rest of the night in a luxury hotel.
Police detained about two dozen Tibetan protesters along the route and in front of the hotel. Many were dragged into police vans as they shouted anti-China slogans.
The torch has been beset by protests through Europe and the Americas, mostly over a Chinese crackdown in Tibet. In some places, protesters tried to snuff out the flame and organisers extinguished or hid the torch to keep it safe.
Fearing similar protests, India trimmed the route to a third of the original 9 km distance, restricting it to a high-security stretch used for the annual Republic Day parade in the Indian capital.
Organisers have so far not even said what time on Thursday the New Delhi leg of the relay will begin.
Thousands of police and paramilitary officers will line the route, which passes close to the nation's parliament and the offices of federal ministers.
Tibetans plan to hold a parallel torch relay on Thursday to protest Chinese action and demand Tibet's independence.
The Dalai Lama, based in the northern Indian hills, has urged Tibetans to desist from disrupting the torch relay, but protests have continued.
India had to assure China of adequate security for the torch after the Chinese foreign minister called his Indian counterpart this month.
A total of 70 torch-bearers, including 45 current and former athletes, will carry the torch.
The torch was in neighbouring Pakistan on Wednesday.