What to mark for race?

So, I am 5/8ths American Indian, but the last people who spoke our native language fluently in my family were my grandmother, and most of my great-grandparents. My great grandparents were mostly ashamed of their ancestry, as it was looked down upon in the urban environments they moved to, and as such, shied away from native culture and did not teach their children about it. It still has a pretty big cultural impact on us though. However, we aren’t native North American, we’re native South American. Because of that, there is not much proof besides the fact that my parents are from countries with large populations of natives.

I’m pretty sure I can mark American Indian and Hispanic on the Common app, but some applications have Hispanic as a race, not an ethnicity, and also have Native American instead of American Indian.

Am I allowed to mark Native American? As far as I know, it means natives to North America, not the other Americas, which is why I am not marked as such in my school system or the US census.

Thanks.