Very risky to use based on what I've read here. A"can" or resin cant be that much cost wise, and even w/o freezing, it has shelf life. There are lots of types of resin too.
That is a very good and sensible question too. The only way to know for sure is to take a little bit of it and mix it up and apply it to some scrap item and see if it sets up and cures. If it does, I'd use it. If not, trash the remaining amount and repurchase... That way YOU will know for certain...
If it's polyester resin it may be ok, heat is more damaging to poly resin than cold. If it's epoxy resin throw it away, epoxy that has been frozen is useless.
Do as gm280 suggests and mix a little up and try it if it's poly resin.