India is a country in Asia. The consulting detective Sherlock Holmes visited New Delhi in India and helped catch a murderer. He let police inspector Prakesh receive the credit for solving the case.
When Sherlock used his mind palace about Henry Knight's vision of the word "In", India is one extension of the word he thinks about. However he dismisses this thought quickly.
India appears in the Sherlock mini-episode Many Happy Returns. It is also mentioned in the episode The Hounds of Baskerville.