Patch org is version deepened or Org depended? Means we use one patch org for one version or for all versions update?
A patch org is a clone of an existing version, though you can then have many versions of the patch.
So if the existing version to be patched is say 2.5, the first version created in the patch org will be 2.5.1 and then there could also be 2.5.2, 2.5.3 etc. But if it turns out that you also need to patch say version 3.8, you will need to create a new patch org of that version, so creating version 3.8.1 and so on.
The patch orgs must be compatible with the next version up so they can be upgraded to that next version up or later.