You'd have to contact the tribes you're interested in (Canada?) to discuss citizenship requirements. Usually, most require proof of direct descent from someone recognized as a citizen (birth certificates or other official records.) Some tribes require blood quantums; full blood, half, quarter, eighth and sixteenth are typical requirements. Simply showing descent from someone who lived in the territory or reservation in the historical time does not establish citizenship. Sometimes, if you can prove descent from a person who was accorded treaty rights (payroll records, per capita rolls, etc.) a tribe may recognize that as proof, but this is difficult to establish.

Several tribes are currently removing citizens from the rolls who were adopted, intermarried (not Indian) or added by treaty (freedmen). In the US, each tribe establishes it's own citizenship requirements. At one time, BIA issued CDIB cards, but now requires you to apply through the tribes before they issue CDIB's. Some tribes used to issue letters recognizing descendants who did not qualify for citizenship (due to blood quantum requirements) usually for purposes of scholarship & program eligibility, etc.