Applying to columbia university-columbia college

current student studying at De Anza College in CA
Well, I am an international student from Korea, and I am 21 yrs old in US(we have different calculation method in counting ages)
I tried to apply to both Columbia University-Columbia college, and Columbia University General studies(GS). But when I called one of the officers of Columbia GS. She said I cannot apply to both schools at the same time. So, I am going to apply to only Columbia University-columbia college.
Somehow, I remember that I saw most students in columbia college are under 21 yrs old. And I am curious whether I can still apply to Columbia college even though I am 21 years old right now.(borned in 1994.april.15th)
Please answer my question by tonight! Cuz The deadline of the application is dur by March 1st
Thanks

Your age shouldn’t matter. Don’t worry

Apply to Columbia College. At 21 years, you are a perfectly normal transfer student. The “traditional” college student is 18-24 years old. The School of General Studies is specifically geared towards older college students, who have a different set of needs and life experiences. (E.g. they may not want to live in the dorms because they already have a family of their own, and they may not want to attend full-time because they want to keep their day job or care for a family member.)

The School of General Studies of Columbia University is the finest liberal arts college in the United States created specifically for returning and nontraditional students seeking a rigorous, traditional, Ivy League undergraduate degree full or part time.

https://gs.columbia.edu/

“Returning” means that you were out of school for several years, and “non-traditional” is a catch-all phrase for anyone with special needs who would not be well-served by the traditional “live in the dorms and attend classes full-time” college model (such as students with children).