You can cheer for whatever team you like. There are no religious restrictions in this matter. Also religion doesn’t require us to be patriotic; it asks us to side with justice instead.
With that said, as humans we don’t exist in vacuums. We live in societies, and those societies have certain expectations from us. For example, your friends and family might expect you to cheer for a certain sports team. There’s nothing wrong with that. If you want to support the rival team instead, there’s nothing wrong with that either. However, if you decide to take a stand for your favorite team despite peer pressure, just make sure that you can do so without having to damage your ties with your friends and family.