This is mostly a Chrome browser issue. But there is a quick fix I found that is working for me.
Let's see what is the new Chrome browser policy regarding videos:
Muted autoplay is always allowed.
Autoplay with sound is allowed if:
User has interacted with the domain (click, tap, etc.).
On desktop, the user's Media Engagement Index threshold has been crossed, meaning the user has previously played video with sound.
In the revolution slider after adding the vimeo video ID go to source settings and enter below vimeo arguments:
The bold part is mandatory if you want your video to autoplay on chrome.
Hope it helps.