Yep, you can have any guests you want as long as your roommate is okay with it. Honestly, there were plenty of guys in Balch when I lived there – it wasn’t that startling or surprising after a while.
I made a post about my experiences in Balch back when I lived there: http://talk.collegeconfidential.com/cornell-university/1761198-housing-why-you-should-consider-balch.html#latest