Tennessee Code Title 16. Courts § 16-15-710

The suing out of a warrant is the commencement of a civil action within the meaning of this title, whether it is served or not; but if the process is returned unserved, plaintiff, if plaintiff wishes to rely on the original commencement as a bar to the running of a statute of limitations, must either prosecute and continue the action by applying for and obtaining new process from time to time, each new process to be obtained within nine (9) months from return unserved of the previous process, or plaintiff must recommence the action within one (1) year after the return of the initial process not served.