I have O365 installed on my rMBP and in my Parallels Win 10 Pro VM, working without issue, Home version. It's seen as two installs. I've also installed the iOS apps on my iPad Pro (the big one); this install requires a Home or Personal subscription but doesn't count against the install quantity. My main want in Windows is Outlook/Excel 2016; the only other app I use is Word 2016 but I only use RTF for my document exchanges.
It doesn't matter which OS you're using, so long as you're licensed properly.