How exactly are placements decided? Region vs Age Group

Some background: I'm an American and already live in Madrid as I'm doing a second master's degree at La Complutense. One of my professors wants me to work on her research team this fall after I've concluded the degree, provided I'm in Madrid, so I applied for NALCAP as a way to stay in Madrid with funding.

My inscrita is 14550, and I listed Madrid as my top choice, Asturias as my second, Galicia as my third. But for some reason I specified that I'd prefer to work with adults over other age groups (which is true, since my tutoring and TA-ing experience has been with adults). Now that I've already submitted, I feel like this preference could limit my chances of being placed in Madrid. But I'm not really sure how the diff parts of the app are weighted.

Does anyone have any insight into how preferences are weighted? Is it really just based on your preferred regions? I want to get my PhD in the US (provided the fed gov doesn't just revoke all funding), and working on this prof's research team would be great for my CV lol