If you get good score in tests like GRE, IELTS and TOEFL, you are simply eligible to get admission in any university of US and many other countries too. Besides, some universities have their specific requirements. Those can be the minimum score in the exams, or any separate test to be given related to the programme you are interested in.
You can find all this information on the website of the universities you are interested in. They provide detailed information regarding all the programmes and requirements.
Additionally, they have a separate section for international students and many of them provide scholarships too.