Various games provide patches but not many provide instructions. Is the name of the patch, i.e. patch.rp or .rpy critical or can it be "game X patch.rp" as long as it is in the right location?
Whatever name the patch is named is what works. You do not need to rename any patches unless you are instructed to in a readme.txt or similar.
Also, know that in a good number of situations, developers aren't making or providing the patches for their games. Someone else not affiliated with the game is making/providing them.
It depends on how the patch works. A Renpy game could be testing whether a file called "patch.rpy" exists. In this case, renaming it would break it. If the patch works via some code inside patch.rpy, the name wouldn't matter.