Russia began to bring troops to Syria in 2015 and started to deploy them in different areas.
Russian forces have been stationed in:
In Tartous Province, Russian forces have also been deployed in Tartoos where it is the most mountainous area. Russia has deployed its S-300 missiles in this area as well.
Russians have

Part of the Russian troops have also been deployed to Latakia which includes:
Hamimim Airport, Estamoo and Salmoo Airports in the depth of Latakia mountains.
Due to the strategic and political importance of these areas, Russia has deployed its S300 and S400 anti-aircraft missiles