As far as I know there are no limits applied to playing the crash game, last time I checked. Any of such limitation is communicated to players on the website, Telegram or at best, spelt out at the hint existing in-game, but none of such. No limits applied. Although you go shoot your query @ the telegram group for more information.
There is not a maximum multiplier, but there is a maximum amount of funds you can win. You see it on every game when you click on "How to play".