all 6 of them in the same room? or 3 per room?
what your budget?
if all in one room
i recommend nihao hostel
go take a look at their family room for 5, it only around 165 per night. 3 single bed, 1 queen size bed and 1 queen size sofa bed and you can top up another 22 dollar to add another extra single bed if you need more. the room is around 30 square m
you can email them at "service@nihao.com.tw" if you have question. That time i email them, they reply within 15 min.
the location is also very good. it located directly next to comso hostel in tms. you go google map look at street view, and you will see how close it is from the exit of the station.