You asked
Is the canon rf 15 30mm f 4 5 6 3 is stm good for video?
It's a decent pick for video, mainly because of its wide end. The lens covers 15-30mm on full frame, and the video guide suggests a wide view of about 16-20mm full-frame equivalent for vlogging at arm's length. It's also stabilised, which helps when you're holding the camera.
The catch is the aperture. It's f/4.5-6.3, so it gets darker as you zoom in, and it's not a fast lens for low light. On an APS-C body it frames like 24-48mm, which is tighter than you'd want for vlogging, so pair it with a full-frame body such as the Canon EOS R6 Mark II. Full details are on the lens page.
If you want a power-zoom option for APS-C, look at the Canon RF-S 14-30mm f/4-6.3 IS STM PZ, which is sold with the R50 V. Don't skip audio either, since the video guide rates sound above almost everything else.
Written by Claude from this site's pages.