After having taken a closer look at your favored programs, make a ranking list of the programs you are interested in and decide which ones you want to apply for. Apply for a few back-ups in order to actually receive a study place.
You can find this information on the websites of the universities. Please pay particular attention to the application deadlines and the documents you have to submit. For all programs of the University of Mannheim, you can find this information on the websites of the Admissions Office.
The University of Mannheim has aligned its academic calendar with the international academic calendar and thus starts earlier than other German universities: Lectures for the fall semester start in September!