Soon you pro-independence Scots are going to outnumber us English around here!!
I do wish Terra had a Scottish themed nation, but it lacks one at the moment.
To answer your question, the game mechanics do not allow for a region within a nation to secede in the technical, on-screen sense of being able to form their own legislature, vote on their own laws, pass their own budgets, sign their own treaties and so on. Of course, with the consent of the other players in a nation, you are free to role-play all manner of scenarios amongst yourselves - including regional secessionist movements. Unfortunately, though, you cannot confine a party to competing in just one region, nor can you necessarily guarantee it will perform more strongly in one region than another.
With the consent of the players involved, roleplays do sometimes take place where one nation occupies another. At the moment, Alduria is rebelling against Luthori, its colonial overlord. You're very welcome to join Alduria (where I'm playing) if that interests you at all. I think Jakania is currently occupied by Luthori as well.
There are non-playable colonies in the game, most of which (I think) are now under the control of Indrala. I suppose you could always talked to the colonial nation players and ask them if they're willing to let you roleplay (in the sense of posting posts on the forum) one of the colonial territories.