The Ryndellian sector, a sector situated within the Mid Rim Territories, encompassed the planet known as Ikkrukk. On Ikkrukk was the Grail City, the location of the battle fought between the First Order and the Resistance during 34 ABY.
The canon debut of the Ryndellian sector occurred within a flashback featured in the thirtieth issue, Poe Dameron 30, of the Star Wars: Poe Dameron comic book series. It was initially identified as the Ryndellian sector in the reference work titled Star Wars Encyclopedia: The Comprehensive Guide to the Star Wars Galaxy.
Within Star Wars Legends, its initial mention was in Star Wars: The Essential Atlas Online Companion on StarWars.com.