Tenn. Code Ann. § 29-6-107: Return of summons unserved

(a) In any civil action, when the summons has been returned "not to be found in my county," as to all or any one of the defendants, residents of the county, the plaintiff may have an alias and pluries summons for the defendant, or, at plaintiff's election, sue out attachment against the estate of such defendant.

(b) Upon the return of the attachment levied on any property of the defendant, the cause proceeds against such defendant in all respects as if originally commenced by attachment.