Explanation:

The Government of India appointed National Income Committee in 1949. The committee was chaired by Prof. P.C. Mahalanobis and had Prof D.R. Gadgil and Dr. V.K.R.V. Rao as members . The first report of the committee was presented in 1951. According to the first report, the National Income of India for 1948-49 was Rs. 8,710 crore and the per capita income was Rs. 225.
Since 1955 the national income estimates are being prepared by Central Statistical Organisation.
The Central Statistical Organisation has divided Indian economy into three basic sector for the purpose of evaluation of various data. They arePrimary sector comprising agriculture, forestry, fishing, mining and quarrying.
Secondary sector comprising manufacturing, power generation, gas and water supply and Tertiary sector comprising transport, communication and trade, banking insurance, computer software, public administration, defence and external trade.
The CSO uses different methods like the Product Method, Income Method and Expenditure method for various sectors in the process of estimating the National Income.