Robert Mor Munro was also one of the members of a Commission appointed to act as Sheriffs of Inverness, for serving Alexander Gordon, 12th Earl of Sutherland, on 30 May 1573. The other members were Colin Mackenzie of Kintail, Lord Hugh Fraser of Lovat and Lachlan MacKintosh of MacKintosh. During the minority of James VI of Scotland, which officially ended in 1578, Robert Mor Munro and Munro of Milntown had charge of the Crown lands of Ross and the Black Isle.