(1) As soon as may be after the commencement of this Act, the population as at the last census of the Scheduled Castes or, as the case may be, of the Scheduled Tribes, in each State shall be ascertained or estimated by the census authority.
     (2) Where by reason of the amendments made by section 3 or section 4—
         (a) any locality in a State specified in relation to any caste or tribe in any of the parts of the Schedules to the Orders referred to in the said sections is varied so as to specify a larger area in relation to such caste or tribe, the census authority shall take into account the population figures of the caste or tribe as ascertained in the last census and in any previous census wherein the population figures of the caste or tribe in respect of the increased area had been ascertained and determine the population of that caste or tribe as on the 1st day of April, 1971 by increasing or decreasing such figures by the proportion in which the general population of the State or, as the case may be, the division, district, taluk, tahsil, police station, development block or other territorial division in relation to which such caste or tribe has been specified by the said amendments has increased or decreased between the previous census aforesaid and the last census;
         (b) any caste or tribe which is deemed to be both a Scheduled Caste and Scheduled Tribe in relation to a State or part thereof is varied so as to specify such caste or tribe only as a Scheduled Caste or Scheduled Tribe in relation to that State or part, the census authority shall take into account the population figures of such Scheduled Caste and Scheduled Tribe as ascertained in the last census:
     Provided that it shall not be necessary for the census authority to determine the population of any Scheduled Caste or Tribe as on the 1st day of April, 1971, if the population of that caste or tribe was not ascertained at the last census and in any of the previous censuses and is, in the opinion of that authority, numerically small.
     Explanation.—Where the population figures of any caste or tribe in respect of any increased area referred to in clause (a) had been ascertained in more than one previous census, the census authority shall take into account, for the purposes of that clause, the population figures of such caste or tribe as ascertained in the previous census which is nearest in point of time to the last census.
     (3) The population figures ascertained or determined under sub-section (2) shall be notified by the census authority in the Gazette of India.
     (4) The population figures so notified shall be taken to be the relevant population figures as ascertained at the last census and shall supersede any figures previously published; and the figures so notified shall be final and shall not be called in question in any court.