Period of which commuted rents are to remain unaltered

Where the rent of a tenure or holding has been commuted under Section 61,- (1) it shall not be increased for a period of fifteen years except,- (a) by order of the Deputy Commissioner, on the ground of a landlord's improvement, or an alteration in the area of the tenure or holding, or (b) by order of a Revenue Officer passed under Chapter XII; and (2) it shall not be reduced for a period of fifteen years except,- (i) by order of the Deputy Commissioner on one of the grounds specified in clauses (c), (d) and (f) of Section 33-A, or (ii) by order of a Revenue Officer passed under Chapter XII.