Apparently Rokas means "Hands" in Lithuanian according to Google translate, which is either a super-cool apropos name for a basketball player or an unfortunate irony, depending on his actual hands. The same holds true for Latvian, if anybody cares. Just on the other Slavic side of the Balto-Slavic language divide are Slovene, where hands is roke, Polish, where it is ręce, Croatian, where it is ruke, and at the far end Russian/Ukranian where it is ruki/ruky. And for bonus in each of those languages, "rocket" is "raketa", presumably because it is a modern word without time for linguistic drift. That's what happens when I have too much free time and nothing to occupy my mind.
Heh, his first name actually doesn't mean anything in Lithuanian. Hand/hands would be ranka/rankos (our best tennis player is Berankis whose name literally means handless/armless, which is ironic for a tennis player). But yeah, the only other meaning that "Rokas" has in Lithuanian is Lithuanianised term for rock music which we also call "rokas". Google translate is still very bad when it comes to lesser known languages like Lithuanian/Latvian.