Section 3 in THE CONSTITUTION (FIFTY-SEVENTH AMENDMENT) ACT, 1987
3. The proposed amendment seeks to provide that if all the seats in the Legislative Assembly of such States in existence on the date of coming into force of this Constitution Amendment Act are held by the members of the Scheduled Tribes, all the seats except one shall be reserved for Scheduled Tribes and in any other case such number of seats as bears to the total number of seats a proportion not less than the number of members belonging to the Scheduled Tribes in the existing Assembly bears to the total number of seats in the existing Assembly.
