There are three other grandchildren by my mothers half sister. She and the youngest grandchild live in his house. I have no copy of a will. Do I have legal rights to it? He lived in Cohes, NY (Albany)
Addtional facts are necessary to answer this question. Is your mother living? If so, you are not an heir at law in your grandfathers estate. If your mother is deceased, you are an heir and will have rights under state law to participate in any probate matter. It may also be possible that you are a beneficiary under your Grandfather's Will or other testamentary document. If so, the executor or trustee is obligated to contact you.
New York law will govern regarding the law in this area. Consult a NY lawyer.See question