Reliable, resourceful, respectful and responsible are nice descriptive words. They begin with the letter r.
Rokko ( very tasty sweet in Turkey )
By nice, do you mean long? Very long list, if you want official list, go to a dictionary. A long word that start with an r would be, Reindeer.
Starting with what? Also, depends on what you call nice.
Radiant is very nice. It begins with the letter r.
Kindhearted is a nice word. Knowledgeable is a nice word.
Right
LustreLoveLikeLimitlessLovelyLadyLimelightLusciousLucky
Raven
immortal
· kangaroo
Quintessential Quidnunc
A six letter word for a bird of prey starting with the letter R is "raptor."