From Star Trek Online Wiki
One of several colony worlds that left the Romulan Star Empire after the destruction of the homeworld in 2387. Rashana Colony is independent, but retains trade and cultural ties with Nova Roma. Surprisingly, Empress Sela has never sent troops to Rashana like she has in other instances of breakaway colonies. Starfleet Intelligence reports indicate that there is still a Tal Shiar presence on the planet, and that might be staying the Empress's hand. While the Tal Shiar work for the Empire, not all of them are loyal to Sela herself.