https://wccftech.com/call-of-duty-black-ops-iiii-battle-royale-mode-to-support-up-to-60-players-rumor/

Call of Duty Black Ops IIII will be the first entry in the series to feature a battle royale mode, but total player count for the mode has yet to be confirmed. It seems like, however, it will be lower than some of the other battle royale games on the market.

A screenshot that has been making the rounds online seems to suggest that Call of Duty Black Ops IIII will support up to 60 players online.