The Delimitation Commission is a statutory and quasi-judicial body established by the Government of India under a specific Delimitation Commission Act enacted by Parliament after every Census. Its origin is rooted in the constitutional mandate to ensure the principle of "One Vote, One Value" by redrawing the boundaries of Lok Sabha and State Assembly constituencies to reflect population changes. The first commission was set up in 1952 under the Delimitation Commission Act, 1952. The problem it solves is correcting the imbalance in representation that arises from differential population growth across constituencies and states.
The mechanism is governed by Article 82 and Article 170 of the Constitution, which mandate the readjustment of constituencies after every Census. The Commission, typically headed by a retired Supreme Court judge, works in collaboration with the Election Commission of India. Its key provisions include determining the number and boundaries of constituencies so that the population of all constituencies is nearly equal, and identifying seats to be reserved for Scheduled Castes (SC) and Scheduled Tribes (ST) based on their population proportion. The Commission's orders have the force of law and cannot be challenged in any court.
The concept is closely connected to the 42nd Amendment Act, 1976, which froze the allocation of Lok Sabha seats to states based on the 1971 Census to promote population control. This freeze was extended until the first census after 2026 by the 84th Amendment Act, 2002. The 87th Amendment Act, 2003, allowed for the internal readjustment of constituencies within a state using the 2001 Census data, without altering the total number of seats allotted to the state. A recent change involved the constitution of a Delimitation Commission on March 6, 2020, for the Union Territory of Jammu and Kashmir and some North-Eastern states, under the Delimitation Act, 2002, and the Jammu & Kashmir Reorganization Act, 2019.