Assuming you will follow the normal schedule and don’t have any study delay, the first moment to choose your own courses is in your third year. In your first and second year you follow courses to obtain 60 ECTS per year so 120 in total. In your third year, the course case studies is compulsory (6 ECTS) and you do your thesis (24 ECTS). Your minor, in which you can choose your courses, therefore normally is 30 ECTS.