The state of Tennessee will not be providing a state-run healthcare exchange for health insurance, but will participate in the federally-managed exchange. Here is the official information from the state of Tennessee website: http://www.tn.gov/nationalhealthreform/exchange.shtml.
To learn more about the federally-managed exchange, go to the Health Insurance Marketplace. The information, provided by U.S. Department of Health and Human Services, gives information on the marketplace and how to enroll. Enrollment starts in October 2013 and coverage begins on January 2014. The site also shows how to get help with healthcare costs now.