grades

Depends on how far below 3.0 and how really tight you are with actives in the chapters. If you are just friends on social media, forget it. Is there some really great reason that you were below 3.0, like participation on state championship level athletic team? Some chapters have a mandated minimum GPA, so they won't be able to consider you, no matter how many friends you have in the house.

Your chances are very slim. There are one or two houses that always have a high chapter gpa and therefore will take a chance on a great pnm who is also a grade risk (less than 3.0) But I can tell you for a fact that you will be cut from a few houses after round 1 due to your gpa. Unless you have extenuating circumstances, having below a 3.0 in high school looks very bad.

You would have a pretty good chance of being cut unless you are a chapter legacy or a very influential chapter alumni wants you.

Maybe phi Mu. That's the only mid tier that MIGHT give you a shot.