Can you play Mount and Blade multiplayer with mods

Get and use MagicLauncher instead of the vanilla Minecraft launcher, and use its "profile" manager to set up one profile with mods for single-player and another profile without mods for multiplayer.

Because it loads mods dynamically, you don't have to alter the minecraft.jar, leaving you a perfectly-vanilla game for multiplayer. In your single-player profile's setup just add the mods to the lists of internal and external mods, and the launcher will add them to Minecraft only when you start the game with the single-player profile. When you want to play online, quit and restart to login with the vanilla, multiplayer profile.

You can get all the patches from the TaleWorlds official website. Just select your game and go to the download section, and it will be here, either in patch or directly download the latest version.

Note that 1.54 should only bring modifications relative to NW, and the mod should work under 1.53 if if doesn't use any NW specific content, So the latest real Warband native version is 1.53, that you already have.