I had never heard of kqueue/kevent. Poking around I found
this pdf document. It looks like a very nice piece of work. I wish it was in all versions of unix. But it looks like it is currently in BSD only. Too bad.
We are not really a realtime os group. But your question "I m wondering whether kqueue/kevent is same as the real-time OS event model." seem to imply that there is a single model for real time OS's. Poking around again I found a couple that were different from each other and did not look "the same" as kqueue. The general notion of an event channel seems to be pretty common though.
I'm going to pass on the api question. Unix is sort of a family of very similiar operating systems. That's rare, perhaps unique. I don't believe that there is similiar family of real-time os's that would enable the writing of very portable applications via a unified api. But I'm not an expert in that area and I could be wrong.