who did informal last year and when?

Zero chance. You shouldn't have dropped.

ASA and DPhiE did open informal last year (not-invitation only). Those are the only chapters that would do anything not by invitation. Informal is held in September usually, unless a chapter severely misses quota at formal, in which case there's informal in February (only DPhiE and Theta Phi did last year, and they probably won't have to this year).

I know dphie and agd did last year pretty much right after rush but that doesn't mean they will this year. I would encourage all pnms who dropped to do informal at any house that offers it. Every chapter at IU is worth a shot

Last year was last year, lots of special circumstances: AGD had a new renovation to fill; ZTA had their entire senior class drop; TPA got a house; ASA, TPA, AGD, DPhiE, ZTA didn't make quota due to all of the drops. This year may be different. Stay tuned.

I think there will be some informal options, however many of those spots will go to women who did not come back from break or women who dropped but were still going back to their chapter, etc. The girls who dropped because they didn't get the chapters back they wanted are not going to be suddenly lucky this time around.

Best thing you can do is follow panhell and social media sites for open informal advertisements. I know I saw signs in the past, posted around campus and facebook posts by friends

All pnms who don't end up joining a house tomorrow should get their friends also not in houses together and go to any open informal available. This will be your last chance to be Greek unless you want to wait a year which would likely have similar results. Every house is what you make it