The Nasib Khan Mosque is located along the southern walls of Old Muscat near al-Bab al-Kabeer. It was built in the late 19th to early 20th centuries by a prominent merchant named Nasib b.Mohammed or Nasib Khan, who also owned a nearby home that is no longer extant. It is one of three prominent Sunni mosques in Muscat, the other two being ‘Ali Musa Mosque and al-Zawawi Mosque. 

Source:

Peterson, J. E. Historical Muscat : An Illustrated Guide and Gazetteer. Leiden ; Brill, 2007, 64, 85, 97.