Only an FFL with proof of payment of class 3 special occupational tax can actually bid on the items. However, the FFL can then transfer these to anyone who goes through the normal NFA $200 tax stamp process. These are pre-'86 transferable M16A1's from the TN Dept of Corrections.
So if you want an M16, find yourself an FFL to bid on your behalf! If these are in good operational condition, market value is probably $15-17k each.
Based on a determination from the National Firearms Act office of the BATFE, these weapons are not subject to the restrictions stated in Public Law 99-308. Individuals may, upon proper approval by BATFE and in accordance with the State and local laws of their place of residence, possess these weapons.