Tenn. Code Ann. § 8-6-403

Service of such civil investigative demand shall be had by a designated representative of the attorney general and reporter handing a copy of the demand to such witness or, if the witness cannot be found, then by leaving a copy of the demand at the residence or usual place of business of the witness. Such process shall run throughout the state, but shall not require any witness to testify in any county other than the witness' county of residence or the county where records or tangible objects demanded are found under the witness' control.