The following statement is true of Montpellier:
- It is the capital of Occitanie.
The other statements are not accurate:
- Montpellier is located in the south of France, not specifically southeastern France.
- It is not one of the smallest towns in France; it is a significant city.
- While it is not one of the largest cities in France (like Paris, Marseille, or Lyon), it is one of the larger cities in Occitanie.
So, the correct answer is that it is the capital of Occitanie.