I'd say NFL players have better chemists in their corner so I'd give them the edge.
If you look at body type most NBA players could problably suceed at QB, WR, CB, or SS for the the most part. Problably same goes for NFL players vice versa. However with exceptions like guys like Shaq (in his hey day) I don't see many players banging in other positions. Maybe you'll string out a few DEs in the NBA but thats about it. I really don't don't get the question entirely but I have much respect for some of the things NFL players do even though I'd say Basketball is more of a pure sport akin the the collision sport that is American Football