Allahabad, officially known as Prayagraj, and also known as Illahabad and Prayag, is a city in the Indian state of Uttar Pradesh. It is the administrative headquarters of Allahabad district—the most populous district in the state and 13th most populous district in India—and the Allahabad division.

https://www.sitesinformation.com/site/ost-pst.us - Prayagrai