Can we submit comment paper to some other journal other than the paper's journal on which we are commenting ?
It might be allowed from journals of the same editorial group (cf. example) if there's a scientific reason to frame the discussion in another journal (e.g. interdisciplinary publications and the comment pertains only one part). Aside from these cases, no.
In other journal is of course allowed to submit full fledge articles that critique or initiate a scholarly exchange with respect to a paper appeared elsewhere. The "comment" format, is specific to articles appeared in a journal and should not be placed elsewhere. It should also be timely, and be submitted within a certain time frame from publication.
You can find the rules specific of your case in the journal webpage and contacting the editor.
Yes, you can submit it anywhere you choose. The question will be only whether it will be accepted there. If your paper has substance then it has a better chance, but that is no different from any other paper.
The original journal doesn't "own" the ideas in any sense at all.
But make the comments substantive. If you can extend (or refute) the original paper, all the better. But bland comments won't likely see publication.