중개업소가 · 중개업소를
brokerage office, real estate agency
Example
동네 중개업소에 가서 원룸을 알아봤어요.
I went to a neighborhood real estate office and looked into studio apartments.
Word parts
중 middle+개 go between+업 business+소 place
Literally 'go-between business place'.
Good to know
In everyday speech people simply say 부동산 for a real estate office.