Although we know there's a versus mode and no co-op in Armored Core 6, FromSoftware hasn't announced any other details about the game's multiplayer officially. However, a snippet of information has allegedly been spotted on the game's box in Japanese stores.
It looks like pre-orders for the game are live in Japanese stores, ahead of its release next month, and a picture shared on Reddit of the box's back reveals that PvP will support up to six players online.
Curiously, at the bottom of the box there's another disclaimer about online multiplayer, which (with some basic Japanese knowledge and some heavy lifting from Google Translate) states that although PvP supports six players maximum, you can actually have up to nine people in a session "including spectators".
According to photos taken in Japan storefronts AC6 will support up to 6-player multiplayer + 3 spectators from r/armoredcore
The idea of being able to host small tournaments with friends inside the game itself is going down well, and I can imagine setting up an off-brand version of Robot Wars with a group of friends would be fun.
FromSoftware hasn't officially announced any details on PvP other than its existence in the game, so we'll have to wait a bit longer to hear whether or not something like a tournament with spectators can be set up in Armored Core 6.
We do know that Armored Core 6 contains references to a fictional drug war, as well as strong language and potentially a brief foray into body horror, but most importantly of all its mechs look extremely slick and powerful.
Our Armored Core 6 preview explains how the game is a polar opposite to Elden Ring and Dark Souls.