Delimitation means the drawing of boundaries. The boundaries may be domestic, national and International, but the most general use of this term is in context with electoral boundaries. Article 82 (Readjustment after each census) makes provision for delimitation of the electoral boundaries. It is the process of allocation of number of Seats and their demarcation into territories.
Under Article 82, the Parliament by law enacts a Delimitation Act after every census. After coming into force commencement of the Act, the Central Government constitutes a Delimitation Commission. This Delimitation Commission demarcates the boundaries of the Parliamentary Constituencies as per provisions of the Delimitation Act.
Delimitation commissions have been set up four times in the past viz. 1952, 1963, 1973 and 2002 under Delimitation Commission acts of 1952, 1962, 1972 and 2002.