What does Naga mean?
From Sanskrit नाग (naga) 'snake, serpent', also denoting the semi-divine serpent beings (nagas) of Hindu and Buddhist lore. Note: classical Sanskrit lexicons record a secondary established sense 'elephant', and the deeper etymology of the word is itself uncertain; the primary and relevant meaning here is 'serpent'.
What does Rupa mean?
From Sanskrit रूप (rūpa) 'form, shape, beauty'. In names it carries the 'beauty' sense; the underlying word denotes beautiful form or appearance.