Is Sonoma 14 the current Mac OS or the current beta?

Sonoma is currently in beta and, if past experience is anything to go by, will be formally released soon enough. Reverting to an older OS involves erasing the disk and starting over from scratch. Unless you have a really compelling reason for doing this I would wait.

I am using this mac OS Sonoma ver 14.0 version. As a result, I have a serious failure in the DaVinci video editing platform. I want to restore the original version. But don't know how to restore it.

It would be rather more simple to contact the makers of that app for an updated version.