A 27 ACT will hurt you – Brown accepts under 10% of its applicants and your score is well below the 25th percentile of admitted students. It is safe to assume that many people taken with ACTs in the bottom quartile have some kind of hook (ex. recruited athlete, child of a big donor etc.). I would work hard to try to improve that score and perhaps study for and try the SATs as well.
https://www.brown.edu/admission/undergraduate/explore/admission-facts