When I was in high school, my sister had a cat that could take down a full grown squirrel, and did on more than one occasion. Still, I've never known of another one.
Generally, so I've read, cats hunt the juvenile rats, a good in itself, but not the full grown ones. Generally predators do not care to be hurt themselves in hunting, so there is a certain size differential they maintain.
Read a short, insightful book called Why Big, Fierce Animals Are Rare, I forget whom it is by.
We have feral cats in our neighborhood. We once found a squirrel head and tail lying on the ground, with most of the in-between all gone. We are sure it was one of the cats.
I'm talking farm cats, not house pets (though some do). We had a calico momma cat, who "kittened" several generations that we kept some kittens out of. She was "the boss" of all her offspring, including the males. They weren't true ferals, as all of them would come to be fed and petted, but otherwise they acted as they a feral group which had our farm as "territory". Any of them could (and did) take rats, squirrels, etc.
And then you have breeds like Maine Coons, Norwegian Forest Cats, etc, that are BIG. I doubt any of them would be even remotely intimidated by any rat.