What are my chances in T-20 Universities? [international, 20/20 GPA, 1530 SAT, 102 TOEFL, IMO bronze, need full financial aid; math, computer science, applied math]

To be thorough in your search, you may benefit from researching the colleges that appear in this topic: For Students Seeking a College Strong in Mathematics. Also, for your combination of interests, you might consider emphasizing schools with an available major or minor in data science.