I took the class on an August Saturday, hit the DMV on a September Tuesday, and the Background Check place that Thursday, and received my permit in the mail on a day in December. It will take them 90 days, to the DAY in Tennessee. And, that's 90 days from the time you complete the LAST step.
I believe that the CCW process in Tennessee is actually a test of one's frustration tolerance. In order to keep people with short fuses from walking around with handguns, the TBI makes it as FRUSTRATING as POSSIBLE to go through the registration process. And, it is... believe me! But, then, once you've got your permit, they KNOW that you're not going to blow up and shoot somebody. You've got to be the Zen Master just to get the stinkin' permit!