If you're being audited, I'm afraid there's usually no quick resolution to the process. It will depend on the workload of the auditor, the number of areas on your return he/she is looking at, and the amount of documentation you'll need to assemble. There's no way to say how long.
If you have the TurboTax audit defense, then use them; that's what you payed for. If you don't have the audit defense, then I would recommend engaging a local tax pro in your area.
Here's a link to the TurboTax audit support page, https://support.turbotax.intuit.com/irs-notice/audit-support/.
