It is the primary business, commercial, and financial hub of Eastern India and the main port of communication for North-East India.[18] According to the 2011 Indian census, Kolkata is the seventh-most populous city in India, with a population of 4.5 million residents within the city limits, and a population of over 14.1 million residents in the Kolkata Metropolitan Area. It is the third-most populous metropolitan area in India. In 2021, Kolkata metropolitan area crossed 15 million registered voters.