if this is a steel rim the crack can be welded. problem I have is why did it crack. if you are the only driver and the rim was not hit/accident I would bring this to the GM dealer for replacement and I would carefully inspect all the rims for cracks.
could also be from tire installers.
alum rims can be fixed at some shops that specialize with this work if not too bad. cracks in alum I would not fix. if bent you can fix alum.which is common with a pothole hit .
your tire if not run long or at a high speed should be good. if the tires are 6 years old I would replace and also with tires off inspect all rims.