Sucks, you really can’t. And grades are like mid-level importance. Research experience and such matters most. In general though, the minimums I’ve seen are like a 3.0 GPA and no one has a GRE minimum anymore. Some schools will post admission statistics, some won’t.

Also, a tip. Go people hunting. Not school hunting. When you get ready to apply, find people that you want to work for, not just school names. If you want to apply to certain schools regardless, find at least 2-3 people you want to work with there. This is the reason why admissions are such a crapshoot. Because you need people to believe in you and believe you are worth a five year investment. It’s not like undergrad where a 15-person council decides your fate. In grad admissions, it’s a smaller council that literally has you list who you want to work with and then brings your name over to said professors to see if you’re worth it.