This is going to be a tough game for Vegas to handicap. The Titans have a new head coach, and we won't know who is starting at quarterback until later in the week...possibly not until Sunday. That is why this game is not on the board at most of the online sites that usually set odds.
One site, BetOnline, has the Titans as an 8 point underdog in New Orleans. That number seems about right to me. The Saints were struggling early in the season to score points, but they have gotten on track the last couple of weeks. To be fair, the defense they have faced haven't been the best, the Colts and the Giants, but Drew Brees is always capable of scoring points in bunches. The Titans defense has been pretty good, however.
On the flip side, the Saints are giving up 29.3 points per game. That is 30th in the league. They are 29th against the pass and 24th against the run. There will be some opportunities for the Titans to put points on the board. Hopefully Mariota is able to play.