How do I get into MIT's RSI?

Answered

next year, I'm assuming? it looks like applications for this year have been closed, and usually big summer programs close their applications early in the year (like February or March)

it looks like it's pretty similar to a college application, honestly, so the same advice should apply. you'll need a baseline of strong grades and test scores, and it looks like they recommend at least a 700 Reading score and 740 Math score on either the PSAT or SAT depending on your year. you'll also need to write essays that demonstrate your interest and achievements in math, science, and technology—which is pretty similar to what you'd have to do to get into a strong engineering college. if you have more specific questions, i can try to answer more exactly.