Hi Ankit,
There are 2 Central Objects that the Regulation is being assigned - Central Objects Subprocess and Controls. How many Regulation object did you create? On what particular Control/Subprocess this regulation is being assigned?
1. You cannot remove the relationship of these objects once a local copy is being created (assigned to an Org Unit).
2. Once you determine the right regulation for it, you may try to remove the relation of it to the local Control and its local Subprocess first.
If you can provide a screenshot, I can also help you through with it.
Hope this helps.
Warm Regards,
Mackoy