To get to Interstate 65 South from Nashville, take Interstate 40 West to Exit 211-B. Then, take the ramp onto Interstate 65 South. Follow Interstate 65 South for about 450 miles until you reach Exit 10-B in New Orleans. Take Exit 10-B and follow the signs to your destination.
This route is the most direct and quickest way to get from Nashville to New Orleans. There are a few other routes you can take, but they will take longer and are not as direct.