I purchased a used vehicle from a dealership,it was represented as a quality used vehicle.I have recently found out that it was a flooded out.

The applicable Louisiana law applies only to cars that have been deemed "totalled" by an insurance company; it does not preclude the sale of water-damaged cars by dealers. You should read the terms of the express warranty you received from the dealer. If that warranty was breached, you can pursue a claim in court.