The N-Br bond is best described as polar covalent.
This is because the bond between nitrogen (N) and bromine (Br) involves the sharing of electrons, but the two atoms have different electronegativities. Nitrogen has an electronegativity of about 3.0, while bromine has an electronegativity of approximately 2.8. This difference is small, but it is enough to cause a slight charge separation in the bond, with the nitrogen atom becoming slightly negative and the bromine atom becoming slightly positive.
In summary, due to the unequal sharing of electrons between the two atoms, the N-Br bond is classified as polar covalent, rather than nonpolar covalent, pure covalent, or ionic.