Section 7(1)(d) in The Bihar and Orissa Local Self-Government Act, 1885
(d)in any district of the Chota Nagpur Division in which the population of the Scheduled Tribes is less than the population of all other communities inhabiting that district such number of members of the Scheduled Tribes, not exceeding two, to be co-opted by the elected members of the District Board in such manner as may be prescribed.