<P> The Chennai Metropolitan Area is one of the largest city economies of India . Chennai is nicknamed "The Detroit of India", with more than one - third of India's automobile industry being based in the city . The city also houses India's Tamil (Kollywood) film industry . In January 2015, it was ranked third in terms of per capita GDP . Chennai has been selected as one of the 100 Indian cities to be developed as a smart city under Smart Cities Mission . </P> <P> The nativity of the name Chennai, being of Telugu origin, is clearly proved by historians . It was derived from the name of a Telugu ruler Damarla Chennappa Nayakudu, father of Damarla Venkatapathy Nayak, a Nayak ruler who served as a general under Venkata III of the Vijayanagar Empire from whom the British acquired the town in 1639 . The first official use of the name Chennai is said to be in a sale deed, dated 8 August 1639, to Francis Day of the East India Company, even before the Chennakesava Perumal Temple was built in 1646 while some scholar argue for the contrary . </P> <P> In 1996, the Government of Tamil Nadu officially changed the name from Madras to Chennai . At that time many Indian cities underwent a change of name . However, the name Madras continues in occasional use for the city, as well as for places named after the city such as University of Madras, IIT Madras, Madras Institute of Technology, Madras Medical College, Madras Veterinary College, Madras Christian College . </P> <P> The name Madras originated even before the British presence was established in India . There have been clear evidences that Madras is not of alien origin. (1) A Vijayanagar - era inscription dated to the year 1367 that mentions the port of Mādarasanpattanam, along with other small ports on the east coast was discovered in 2015 and it was theorised that the aforementioned port is the fishing port of Royapuram . There are also suggestions that it may have originated from a Portuguese phrase mãe de Deus, which means "mother of God", due to Portuguese influence on the port city, specifically referring to a Church of St. Mary . According to some sources, Madras was derived from Madraspattinam, a fishing - village north of Fort St George . However, it is uncertain whether the name was in use before the arrival of Europeans . The British military mapmakers believed Madras was originally Mundir - raj or Mundiraj . </P>

When change the name of madras to chennai