You most probably are looking for housing to share with other international students. If you are still abroad, you do not have a network yet in the city you are going to study. Fortunately the internet can help you out. We found some groups and pages on social media. Have a look and consider inserting a post to find your flatgroup. Put the information in your post that you think is important for you. You will attract students who recognize what they think is important too.
Social media platforms for international students
Contact students abroad
Before passing your exams, you already know where and when your next study will begin. Ask your school or other pupils if they know who moved to Rotterdam a year or two years earlier. The students who are already in Rotterdam know where to look or can even do a viewing for you.