Sector Z-6 was a region of space in the Alpha Quadrant. This sector encompassed the territory of the United Federation of Planets and the Romulan Star Empire. The Romulan Neutral Zone bisected this sector. On the Federation side of the zone, there were several outpost stations.
In 2266, the Neutral Zone Incursion occurred in this sector. (TOS: "Balance of Terror", display graphic)
List of objects in sector
"The Explored Galaxy" was a map of charted space in the Alpha Quadrant. The Romulan Neutral Zone was located between the Tholian Assembly and Romulus. Both locations were identified in DS9: "The Search, Part II", "Call to Arms" as being located in this quadrant. The chart, first seen chronologically in Star Trek VI: The Undiscovered Country, was also seen in several Star Trek: The Next Generation and Star Trek: Deep Space Nine episodes set in the 24th century, from the year 2364 to 2370. These were TNG: "Conspiracy", "The Measure Of A Man", "The Emissary", "The Mind's Eye", "The Game", and DS9: "In the Hands of the Prophets", "Cardassians".
According to the Star Trek: Star Charts (pg. 66), this sector was in the Romulan War Theater of Operations (2156-60).