Can a red-tail hawk be a pet to humans?

No, unless you have a license. Hawks are an endangered species. They are a protected animal and you can only own a hawk with proper training and license.They must be fed, trained and handled properly. They are very difficult birds to deal with. They can die if not cared for properly and are potentially dangerous to you if you don't know how to handle them. They also need lots of wild space to fly.

I suggest you don't buy one, unless you're a challenge lover with license and lots of training.