Section 37B(i) in The Rajasthan Land Reforms and Resumption of Jagirs Rules, 1954
(i)Where royalties are payable on account of mines and minerals, the average income on account of the royalties calculated on the basis of the annual return filed by the Jagirdar for the assessment of cess or income-tax during the period of 6 years preceding the agricultural year in which the date of resumption of the Jagir falls or any short period for which such returns have been filed.