The delimitation exercise is a concept and an act of fixing the limits or boundaries of territorial constituencies for the Lok Sabha and State Legislative Assemblies in India. Its primary objective is to ensure that the number of people represented by an elected representative remains roughly the same, upholding the principle of 'one citizen, one vote, one value'.
The process is rooted in the Constitution, which mandates readjustment after every Census through Article 82 (for Lok Sabha) and Article 170 (for State Assemblies). The first post-independence exercise was carried out in 1950-51, and the first statutory body was established under the Delimitation Commission Act, 1952. The exercise was frozen in 1976 by the 42nd Amendment Act to encourage population control, preventing states that successfully controlled their population from losing political representation.
The mechanism involves the Parliament enacting a Delimitation Act, which leads to the formation of the Delimitation Commission, a statutory and quasi-judicial body. The Commission is chaired by a retired Supreme Court judge and includes the Chief Election Commissioner. The Commission uses the latest Census data to redraw boundaries and determine seats reserved for Scheduled Castes and Scheduled Tribes, as mandated by Articles 330 and 332. A key provision is that the Commission's orders have the force of law and cannot be called in question before any court, a principle upheld in Meghraj Kothari v. Delimitation Commission and others (1967) to prevent indefinite delays in elections.
The inter-state allocation of seats has been frozen since the 1972 delimitation based on the 1971 Census. The 84th Amendment Act, 2002 extended this freeze until the first census taken after the year 2026. While the total number of seats remained the same, the boundaries within states were redrawn based on the 2001 Census under the Delimitation Act, 2002. Recently, the most significant change was the delimitation for the Union Territory of Jammu and Kashmir in 2022. There are current proposals to expedite the next nationwide exercise, potentially using the 2011 Census data to implement the Women's Reservation Act, 2023, which could increase the Lok Sabha seats from 543 to 816.