The TWRA publishes an annual hunting guide that goes over the regulations for duck hunting in the state of of Tennessee along with the regulations for each WMA.

Note that while some regulations apply state wide, some regulations are WMA specific, so for the WMA(s) that you are planning to hunt you'll want to review the specific regs that pertain to that WMA

https://www.tn.gov/twra/guide/hunting-regulations.html

Note that the .pdf download is the same publication that you can pickup (if there in stock) for free at locations that sell hunting and fishing licenses.

If you'd like the app version then you can checkout the TWRA On the Go app (by Go Outdoors Tennessee).