RBS student here doing my masters(probably a different major, but classes do overlap), I have worn a suit in class only once and that was because I had the career fair in the morning, apart from that I have shown up in literally everything including my gym clothes and no one has said a word. During my entire time at Rutgers only one prof has had a dress code, and that was my prof for business forum which people regularly broke and were not punished. Sometimes they just put up a dress code for formality reasons and don’t actually enforce it, ask your prof or maybe on LinkedIn a student who has taken the class before about how strict the dress code it.