Your result
Argentina — Citizenship by Descent
Possible
We can place you as soon as one fact is settled, and it is usually an easy one to settle.
Argentina's descent route turns on a single distinction: whether the Argentine person you descend from was born in Argentina, and whether that person is your parent rather than someone further back. A parent born in Argentina gives you a strong and fairly straightforward claim. A parent who became Argentine some other way, or a connection that starts at a grandparent, leads somewhere quite different.
Nothing about your case is unpromising. This is missing information, not a bad answer.
The document that settles it is an Argentine birth certificate for the relative in question, or their DNI. An old passport, family papers, or the place of birth recorded on a marriage certificate are often enough to point us at the right one.
Send us what you have, even if it is only names and approximate years, and we will tell you which of those situations you are in.