There are students who get Regents from either UCB or UCLA but have a low chance of getting accepted to HYPSM, and then there are kids like my kid who get accepted to one of HYPSM but have a low chance of getting Regents. Although I am not very familiar with how UCs select Regents scholarships, I did bump into some students with not that high GPA and test scores but with financial need who were surprised they were selected for Regents.
Having said this, you might get it, who knows?