Ah, I understand what you're after now. Well, you've got to know where the planet is really situated to begin with in the first place, or have some vague idea of where it is. Nar Shaddaa is in the South-East area of the map, in a large sort of bubble looking thing. It is in Hutt Space, and near Da Soocha V, Ylesia, Nal Hutta, Barab I and Rinn. I hope that helped.