The 84th Amendment Act, 2001, is a Constitutional Amendment Act that primarily concerns the delimitation of parliamentary and assembly constituencies in India. It was enacted to extend the freeze on the total number of seats in the Lok Sabha and State Legislative Assemblies, a measure originally introduced by the 42nd Amendment Act, 1976, which was based on the 1971 Census figures. The core purpose was to incentivize states to pursue population stabilization policies without the penalty of losing political representation in the Parliament and State Assemblies.
The Act amended several articles, including Article 81, Article 82, and Article 170, to extend the freeze on the total number of seats allocated to each state until the first census published after the year 2026. This effectively means the total number of seats, which is based on the 1971 Census, will remain unchanged until at least after 2031. However, the Act introduced a key mechanism: it permitted the readjustment and rationalization of territorial constituency boundaries within a state, without altering the total number of seats. Initially, this internal readjustment was to be based on the 1991 Census figures. This provision was later modified by the 87th Amendment Act, 2003, which changed the basis for the internal delimitation exercise to the 2001 Census. The Act is intrinsically connected to the concept of Delimitation and the work of the Delimitation Commission, ensuring that the principle of "one citizen-one vote-one value" is maintained within a state's existing seat allocation.