Please choose an indigenous group, past or present. There is a long list of such groups here: https://en.wikipedia.org/wiki/List_of_indigenous_peoples.
First, start with the facts. What was taken from or is being taken from this group and how by whom? For example, what parts of their culture have been or are being lost, and was their land taken?
Second, what is the applicable international and domestic law? There is an overview of the rights of indigenous peoples here: https://en.wikipedia.org/wiki/Indigenous_rights.
Third, what is your group doing and with what degree of success to try to recover what was taken from them, such as through local festivals, literature, the courts, lobbying the government, or activism?