Does the Disc work on XB1

does the disc version of reach work or will it say its unreadable because i dont want to spend more than $7.00 on it for christmas

Yep the disc works. You have to download a 7Gb update for it.

Thanks i didnt want to risk spending my money for it not to work

Yeah, they released an update that allowed the game to be backwards compatible. (Even though your question was already answered, I felt like saying it).

Just downloaded mine today.