Ok, I'm going to explain this to you as well as correct your sentence. The sentence should be worded like this:
Mr. and Mrs. Douglas are at a travel agency getting some information about their tours.
Their in this sentence refers to Mr. and Mrs. Douglas. It's a posessive pronoun meaning that Mr. and Mrs. Douglas are the people and the tours belong to them, thus it is their tours.
Hope this helps.
Ali aka FLHomeschoolMommy
Student or Learner