In 1876, we can see that the regions of Nikshiq (Nikšić), Presjeka, Goransko and Gacko was indeed inhabited by Muslim Albanians, as they publicly surrendered to the Prince of Montenegro.

“It is written from Ragusa, July 6th. The Muslim inhabitants of Niksic, Presjeka, Goransko, and the Gacko plateau have sent a petition to the Prince in which they request protection for their lives and property. “We are subject to kismet,” reads one passage in the petition. “Crna Gora, we will not fight. We surrender our weapons to You. Command, Gospodar, that our lives be spared, that our houses not be destroyed. We submit to the decree of Allah and seek mercy from You.” The Prince has indeed ordered that no village should be burned, no castle bombarded, until three attempts at surrender have proven unsuccessful.”

Reference

Augsburger Abendzeitung politischen, historischen u. gemeinnützlichen Inhalts. 1876, 7 – 9.