XBOX LIVE Disc Compatibility for Region (NTSC and PAL)

Hi

I want to buy the XBOX LIVE Namco Arcade Museum disc. It comes as NTSC and PAL.
If my brother bring we one from USA (NTSC) will the disc works in by XBOX ONE.
I am from South Africa, Fall under Europe region (PAL) some games.
My understanding XBOX ONE is region free so that disc should work?
Or must I buy the PAL version? I notice on the internet importers did import the PAL
version way back then. if the NTSC version will work then I rather buy that one.
Please help... If I buy the NTSC and it do not load the XBOX LIVE because of some region code
I will lost a lot of money due to rand/dollar exchange and postage cost is high.