The Verdict: Not eligible
An ancestor who lived in the Dutch East Indies does not give you Indonesian citizenship, because the citizenship began with the republic and passes only from a parent. If that ancestor later held Indonesian citizenship, you may still be able to live there.
Indonesia declared independence on 17 August 1945. Many families with roots in the colony, including many Indo-Dutch, Chinese and Arab families, left around independence and never held Indonesian citizenship.
What to check: if your ancestor did hold Indonesian citizenship at any point after 17 August 1945, and you are their child or grandchild, the Global Citizenship of Indonesia scheme may give you a permanent stay permit. Our Diaspora quiz for Indonesia covers it. If they never held it, there is no family route, and the ordinary residence routes in our other Indonesia quizzes are the way in.