Chennai , formerly known as Madras , is the capital of the state of Tamil Nadu and is India's fourth largest metropolitan city. It is located on the Coromandel Coast of the Bay of Bengal. With an estimated population of 6.91 million (2006),http://www.world-gazetteer.com/wg.php?x=&men=gpro&lng=en&dat=32&geo=-104&srt=pnan&col=aohdq&pt=a&va=&geo=-1048954 World Gazetteer: Chennai agglomeration the 368-year-old city is the 34th largest metropolitan area in the world.