true that you need connections to get in top tiers?

Yes the higher the tier the more competitive to get into the frat, and it's even harder as a sophomore compared to as a freshman. I've heard of people who've gotten into top tiers without connections but those are incredibly rare, most of the people who get into those really competitive places know people in the frat (but even if you know brothers it doesn't always mean you'll get a bid). Rush everywhere and just join wherever you fit man, that's all that really matters in the end.

Dress well, get to know the guys, go to many places, all the usual stuff that will increase your chances. Just remember there are no guarantees so I'd recommend rushing frats from every tier. People have a good time in every tier don't overthink it