Need to find out about legal options for a home in my son's family that is in the name of his deceased grandmother.

Your son has a mess on his hands, I'm sorry to say. If his grandmother died without a Will, and if your son's father was the only heir to his mother, and if his father also died without a Will and the son was the only heir, then the title to the property may have passed to your son. He will still need to clear title, but he may be able to do this without opening either estate. However, if either the grandmother or the father had any unpaid debts, then the property may well be subject to those debts (including your back child support debt), and he may not be able to get clear title without opening and administering the estates (both of them). Also, if the grandmother had a Will, then the waters are muddied. Same thing if the father does have a Will. Effectively, the existence of a Will at either level interferes with the transfer of title by intestacy law, because if a deceased person has a Will, the intestacy rules do not apply and the property is likely stuck in someone's estate until that estate is administered. The Wills could have also transferred the property to someone outside of the heirs chain, which could prevent it from coming to your son at all. Your son needs to get a consultation with an actual attorney in person. He also needs to dig up as much information as possible to see whether there might be any Wills out there, as well as proof that his father would have been his grandmother's only heir and proof that he would be his father's only heir. Then he can find out what his options are. As for your debt for back child support, it would be a claim against the father's estate, but if the house is foreclosed on for property taxes any sales proceeds above that amount would likely be required to be paid to the estate of the owner. That means you wouldn't get paid directly; instead, someone would still need to open the father's estate and, possibly, the grandmother's estate, too.