Tenn. Code Ann. § 66-8-110

The person proposing to redeem shall always pay, or tender, to the holder of the land, the amount of money lawfully paid by the holder, with interest thereon, at the current composite prime rate as published by the federal reserve board as of the date of purchase per annum; and, if the holder is a creditor, shall pay to the debtor or credit the debtor's debt with a sum equal to ten percent (10%) or more on the sum bid at the original sale, or with a sum equal to ten percent (10%) or more upon the judgment of the creditor, at the election of the creditor.