Shantil III
From Star Trek : Freedom's Wiki
Shantil III is the third planet in the Shantil system and homeworld of a sentient species. It was the site of a mytho-historical drama, in which the figures Darmok and Jalad faced a common foe on the island-continent of Tanagra, and achieved mutual understanding in the process. The story was later incorporated into the Tamarian language. (TNG: "Darmok")
It is likely that this is the homeworld of the Tamarian species.