Techically tribal membership is a political status not a racial one. You must contact both tribes to determine your eligibility for membership. Each tribes sets their own criteria for membership. This information may be found on the tribes website or by calling their enrollment/membership department. You may also find information by doing a web search of the Bureau of Indian Affairs. At a minimum you will need your mother and father's birth certificate, your family tree, and a copy of the enrollment information from the relatives you believe are enrolled members. Most tribes have some bllod quantum requirement. Good luck!
This is not intended as legal advice. It is only provided for educational purposes and cannot be relied upon as legal advice. Further no attorney client relationship is or has been formed by answering this question.