Tenn. Code Ann. § 7-32-124: Failure to object to assessments

(a) If no objection to the assessment or the amount of the assessment is filed, or if the property owners fail to appear in person or by attorney and present the objection, the assessment shall be confirmed and made final.

(b) Property owners who do not file objection in writing or protest against the assessment shall be held to have consented to the assessment and are forever barred to attack the regularity, validity, or legality of the assessment.