What can "ranges" mean in this context?

Solution 1:

It means the same as the first range in the sentence - a group of things of the same general type. The shops sell a wide range/selection/variety of gifts, of which some types are sold only at the Castle.

Solution 2:

"The castle’s three gift shops sell a wide range of high quality gifts, books and souvenirs including exclusive Edinburgh Castle ranges"

This says that within the wide range, there are several narrower ranges! It's not very well written.

Possible alternative

"The castle’s three gift shops sell a wide selection of high quality gifts, books and souvenirs including exclusive Edinburgh Castle ranges."

Note

We can only speak about English on this forum. If you want to check a translation or meaning, a better place to ask might be such as https://forum.wordreference.com/