Section 7(2) in Tamil Nadu Village Panchayats (Assessment and Collection of Taxes) Rules, 1999
(2)When a progressive rate has been adopted by the village panchayat, it shall -(i)specify the principles of classification (as that a certain sum, which shall be tax-free, shall be deducted from the assessment of each house, or that the progression shall be from a certain percentage in the lowest to a certain percentage in the highest class); and(ii)settle the precise number and limits of each class.
