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.
[Penalties for illegal exaction of praedial conditions or of anything in excess of rent or of local cess]