Delhi was a city located in India. There was a branch of Torchwood located here, led by the Duchess. (AUDIO: Golden Age)
In 1885, the Vespiform Christopher came to Earth here to learn about the planet. While there, he met Clemency Eddison, and fell in love with her, giving her the Firestone. He drowned in a great monsoon, when the Jamuna River flooded its banks. (TV: The Unicorn and the Wasp)
Iris Wildthyme visited Delhi at least twice. On her second visit, she recognised the 14th century Pathan architecture, and the Lodi Gardens, which she knew as the Lady Willingdon Gardens from earlier in its history. (PROSE: The Story Eater)