The Code of Criminal Procedure, 1973 (CrPc)
8. Metropolitan areas.
(1) The State Government may, by notification, declare that, as from such date as may be specified in the notification, any area in the State comprising a city or town whose population exceeds one million shall be a metropolitan area for the purposes of’ this Code.
(2) As from the commencement of this Code, each of the Presidency-towns of Bombay, Calcutta, Madras, and the city of Ahmedabad shall be deemed to be declared under sub-section (1) to be a metropolitan area.
(3) The State Government may, by notification, extend, reduce or alter the limits of a metropolitan area but the reduction or alteration shall not be so made as to reduce the population of such area to less than one million.
(4) Where, after an area has been declared, or deemed to have been declared to be, a metropolitan area, the population of such area falls below one million, such area shall, on and from such date as the State Government may, by notification, specify in this behalf cease to be a metropolitan area; but notwithstanding such cesser, any inquiry, trial or appeal pending immediately before Such cesser before any Court or Magistrate in Such area shall continue to be dealt with under this Code, as if such cesser had not taken place.
(5) Where the State Government reduces or alters, under sub-section (3), the limits of any metropolitan area, such reduction or alteration shall not affect any inquiry, trial or appeal pending immediately before such reduction or alteration before any Court or Magistrate, and every such inquiry, trial or appeal shall continue to be dealt with under this Code, as if such reduction or alteration had not taken place.
Explanation. In this section, the expression “population” means the Population as ascertained at the last preceding census of which the relevant figures have been published.