Boxed copies arrive 12 November, but there's no disc inside
The physical edition is a download code, released a week early so buyers can pre-load too.

Physical copies of GTA 6 go on sale on 12 November, a week before launch. The box contains a download code instead of a full game disc.
Rockstar is releasing them early so physical buyers can redeem the code and pre-load like everyone else. You'll still need the full 212 GB free and an internet connection to install.
Does it matter?
If you were planning to buy physical to save on bandwidth, it won't help. If you want something to gift or a code you can buy in a shop, it works the same as digital, bonus included if bought before 20 November.