The last obvious thing we get that specifically addresses Orcs is at the Black Gate right after the One Ring is destroyed. In Peter Jackson’s film adaptation of “The Return of the King, the land around the Armies of the West conveniently crumbles, consuming all of Sauron’s minions and leaving Aragorn and Company with minimal cleanup. The book version isn’t quite so clear-cut. It says the Men of Rhûn and Harad either flee or fight to the death. It also says, “the creatures of Sauron, orc or troll or beast spell-enslaved, ran hither and thither mindless; and some slew themselves, or cast themselves in pits, or fled wailing back to hide in holes and dark lightless places far from hope.” So, a few clearly survive, but they’re masterless and on the lam.
A bit later in the book, it adds the non-specific line that, as king, Aragorn gives the lands around Lake Núrnen in Mordor to a group cryptically called “the slaves of Mordor.” In the appendices of the book it also says, “For though Sauron had passed, the hatreds and evils that he bred had not died, and the King of the West had many enemies to subdue before the White Tree could grow in peace.” Technically, Orcs could be part of the slaves of Mordor and the evils Sauron had bred, but the reference doesn’t clarify if that is the case.
Finally, there’s J.R.R. Tolkien’s abandoned “Lord of the Rings” sequel. The brief story takes place decades later. By then, Men are everywhere and Orcs have become semi-mythological beings. Even so, the draft and Tolkien’s letter about it do reference “Orc’s work,” “orc-cults,” and Gondorian boys pretending to be orcs and doing damage.
