I want to add a 5TB HD (NTFS) to my time capsule and have access to it from both my Mac and my PC's

I want to add a 5TB HD (NTFS) to my time capsule. I have both Mac and PC's and will like to access the drive from both. I can see that the drive is attached in airport utility on my windows pc but I can't access it(probably because of the NTFS partition). I am not seeing anything at all in airport utility on my Mac (probably because it's not in HFS+ format). I think I can partition the drive into two drives, one NTFS and the other HFS+ but I will only do that if it's my only choice. I would rather have access to everything from both Mac and PC............

HELP!!!