Section 120(6) in Haryana Panchayati Raj Act, 1994
(6)One seat in every Zila Parishad shall be reserved for the persons belonging to Backward Classes and such seat shall be allotted to such wards having maximum population of persons belonging to Backward Classes:Provided that reservation of seats under sub-sections (1), (2), (3), (4) and (6) shall be reviewed after every decinnial census.