This guide will show you how to enable and access multiplayer game modes for Revision, including Deathmatch and Revision exclusive Survival.
Second, go to your installation folder: Program Files (x86)\Steam\steamapps\common\Deus Ex\Revision\System and open Revision.ini. Search for each instance of Paths=..\NewVision\Textures\*.utx and add a semicolon to the start of it. This will disable the New Vision HD wall textures, and allow other people to connect to your servers or you to theirs.
After this you can load Revision, open the main menu and press the ‘Back to Game’ button to access multiplayer options.
If hosting a survival map, make sure to set the game type to survival too instead of deathmatch.