25. In preparing or revising a record-of-rights under this Chapter, the Revenue-officer shall determine the fair and equitable rent of all non-agricultural lands held by non-agricultural tenants other than a tenure-holder in accordance with the provisions of section 23 so far as they apply to non-agricultural lands: Provided that when any such tenant holds any such land immediately under any person other than a proprietor or a tenure-holder, the Revenue-officer shall presume the existing rent payable by such tenant for such land to be fair and equitable unless it exceeds by more than fifty per centum the fair and equitable rent payable in respect of such land by such person; and if it so exceeds, the Revenue-officer shall fix the rent of such land so held by such tenant at a rate not exceeding the rate of the fair and equitable rent payable for such land by such person by more than fifty per centum.