unity multiplayer with websocket controller running on a webserver.

I am building a game that uses websocket to connect to an android controller (made with html5 + js) for multiplayer. The actual version runs locally as a standalone app and works as intended, people can connect and play it locally as a multiplayer.

The question is that now the scope was changed and they want the game to run totally on a webserver. I am trying to figure out if it is possible, what i will have to do and how much time\work will it cost.

The game is totally made to run as a standalone till now, the first thing will be to change it to a propper multiplayer(multiple instances). It has to be acessible from anywhere, he wants it to be in webgl and the server must run multiple instances of the game.

Thank you all for the attention.