UMass interviews >50% of instate applicants so that would be your best shot, but unfortunately it's MA's only public institution. 58% translates to about an 8, and 506 translates to about a 29. Since UMass has an MCAT median of 33 with a 10% at 29, I would DEFINITELY recommend applying to DO schools as well lower tier MD schools. If you want to be a doctor it shouldn't matter if its an MD or DO by the name.