There's no official "Scotland" civilization in Civilization V, but you have several ways to lead the Scots to victory—whether through DLC, custom creation, or community mods.
Search for "Scotland," "Highlanders," "Celtic," or "British Isles." Quality varies—read descriptions, check compatibility with your DLC (especially Gods & Kings and Brave New World), and look for recent updates. Popular mods often include custom leader art, unique music, and balanced abilities.
With a little setup, you can absolutely guide Scotland to a cultural, scientific, or domination victory.