"Two hands. One to destroy, the other to save. Which had he lost?"

In the end of the book, one could say he "lost" the hand to destroy, namely the male Choedan Kal.

Besides that, one could also say that Taim was Rand's "hand" at the BT. It's clear that he will lose him alongside Taim's ca. 100 cronies.

Finally, Rand might also lose parts of his empire to the Shadow or the Seanchan.

Of course, the reason for the hand losing was to make Rand more like the Norse God Tyr.