<P> The Scheduled Castes (SCs) and Scheduled Tribes (STs) are various officially designated groups of historically disadvantaged people in India . The terms are recognised in the Constitution of India and the various groups are designated in one or other of the categories . For much of the period of British rule in the Indian subcontinent, they were known as the Depressed Classes . The combined percentage of people in scheduled castes and scheduled tribes is essentially the official percentage of people in the lowest part of Indian society . </P> <P> In modern literature, the Scheduled Castes / Tribes are sometimes referred to as untouchables; in Tamil Nadu they are referred as Adi Dravida; and in other states mostly referred as scheduled castes . </P> <P> The Scheduled Castes and Scheduled Tribes comprise about 16.6% and 8.6%, respectively, of India's population (according to the 2011 census). The Constitution (Scheduled Castes) Order, 1950 lists 1,108 castes across 29 states in its First Schedule, and the Constitution (Scheduled Tribes) Order, 1950 lists 744 tribes across 22 states in its First Schedule . </P> <P> Since the independence of India, the Scheduled Castes and Scheduled Tribes were given Reservation status, guaranteeing political representation . The Constitution lays down the general principles of positive discrimination for SCs and STs . </P>

Sc st population in india as per 2011 census