The first population census in British India was conducted in 1872. Since 1951, a census has been carried out every 10 years. The census in India is carried out by the Office of the Registrar General and Census Commissioner under the Ministry of Home Affairs, and is one of the largest administrative tasks conducted by a federal government.
The latest population figures are based on data from the 2011 census of India. India has 641,000 inhabited villages and 72.2 percent of the total population reside in these rural areas. Of them 145,000 villages have population size of 500–999 persons; 130,000 villages have population size of 1000–1999 and 128,000 villages have population size of 200–499. There are 3,961 villages that have a population of 10,000 persons or more. India's 27.8 percent urban population lives in more than 5,100 towns and over 380 urban agglomerations. In the decade of 1991–2001, migration to major cities caused rapid increase in urban population. The number of Indians living in urban areas has grown by 31.2% between 1991 and 2001. Yet, in 2001, over 70% lived in rural areas. According to the 2001 census, there were 27 million-plus cities in India, with Mumbai, Delhi, Kolkata, and Chennai being the largest.
There are 53 urban agglomerations in India with a population of 1 million or more as of 2011 against 35 in 2001. About 43 percent of the urban population of India lives in these cities. Among these cities Srinagar, has become the first agglomeration in Jammu and Kashmir to cross one million. Kerala has added six new million-plus agglomerations in addition to Kochi, the only such area in 2001.
^The population figures of cities in Kerala are inflated as the definition of urban agglomeration was revised in the 2011 census. The population of urban agglomerations in Kerala is not comparable with other cities in the country.