Anchorman is purely fictional. The characters and events are made up to provide comedic and satirical entertainment. There's no real-life basis for the plot.
Well, 'Anchorman 2' is indeed based on a true story to some extent. It takes elements from the history of news broadcasting. For example, the general atmosphere in newsrooms, the competition among anchors, and the changing trends in news reporting are all things that have real - life counterparts. However, it exaggerates and fictionalizes a great deal to make it a hilarious comedy.