Yes, if you have registered your copyright, you have the right to sue. However, if you are not registered, there can be some restrictions on suing another party for infringement and enforcement of your copyrights. For example, original work can be registered anytime, before or after the infringement. However, if you register your work after the infringement, you could lose your right to statutory damages, which are the high-level damages awarded in copyright infringement cases. But there is a bit of a leeway provided. For instance, if the work was registered within three months of publication after it was infringed, you can still be awarded statutory damages.