Anything can be mounted anywhere, just a matter of how much it is going to cost!
As for who can mount anything anywhere, some people are more skilled at making custom wood pieces which would hold something to be mounted somewhere. Others can do welding of metal brackets or know how to go to a welder to get a bracket made. People would have the tools to do these various things - saws, welders, drills, drill bits, ladders, etc.
And then some do-it-yourself types may not have much of any tools or skills to mount things and would need detailed directions as to how to mount it - best in that case if the camera is specifically made to be mounted on the top of a roof peak, but I don't recall any that are.
Do you want it on TOP of the roof? And to be able to look around an entire circle?
Or on top of the roof and just look out say half a circle? (A mounting bracket could be behind it.)
Or mounted on the wall high up?