For the getter methods, it looks like you need to use if logic to determine what to return. It looks like the constructor initializes the title and quantities for each format (DVD and Blu-ray) that are in stock. So, if you look at the getMovieStock(char which) method, how will that method know whether you want the stock number for the DVD or Blu-ray of say The Dark Knight? It uses the 'char which' method parameter. So if it uses a method parameter you will need to have if logic that will determine what stock number to return for the format the user requests. Here is what I would do. Use this type of logic for the other methods. Assume that types of movies have chars 'D' for DVD and 'B' for Blu-ray.
As you can see, if movie is a DVD it will return the intMovieDVD amount, otherwise the movie is a Blu-ray and it will return the stock amount of intMovieBlueRay. As I said before you need to use similar logic for your other methods including the setters. If not, how will they know what variables to update?