The rent payable by a tenant shall, subject to the maximum fixed under section 11, be the rent agreed upon between such tenant and his landlord or in the absence of any such agreement the rent payable according to the usage of the locality or if there is no such agreement or usage, or where there is a dispute as regards the reasonableness of the rent payable according to such agreement or usage, the reasonable rent determined by the Tahsildar in the prescribed manner having regard to the rents prevalent in the locality, the productivity of the land, the prices of commodities and such other factors as may be prescribed:
Provided that the Tahsildar may after inquiry on an application by the tenant or landlord at any time during the currency of the tenancy,-
(i) reduce the rent, if he is satisfied that on account of the deterioration of the land by flood, or other cause beyond the control of the tenant, the land has been wholly or partially rendered unfit for cultivation, or
(ii) subject to the provisions of section 11, enhance the rent, if he is satisfied that on account of any improvement made in the land, at the expense of the landlord, there has been an increase in the agricultural produce thereof.