my son has one child and getting a Divorce I cosign for a house a year ago who gets the house

Cosigning does not make you an owner.  It just makes you liable to the mortgage company if the mortgage is defaulted on.  If your son and his wife purchased the house during the marriage in both their names, then they jointly own the house.  A Petition to Partition Community Property would need to be filed with the court to split the house and other assets.