Sefalla Prime

Sefalla Prime was the prime planet in its star system. This planet was located near Draylon II.

When Commander Sisko and Major Kira were considering Draylon II as a possible site for relocating the Skrreea population in 2370, they noted that the planet was near Sefalla Prime. (DS9: "Sanctuary")

This planet was only mentioned in dialogue.
Based on the planet's seemingly close proximity to Draylon II, it would seem that this planet is in, or is relatively near the Alpha Quadrant.
According to StarTrek.com, Sefalla Prime, in orbit of the star Sefalla, was located in the Sefalla system, which was located in the Bajoran sector. [1](X) [2](X)