The origin of the collinear antiferromagnetic magnetic structure of Ni3TeO6 below 52 K was analyzed by calculating its spin exchanges on the basis of density functional calculations, and the cause for the lie-spin orientation found for this magnetic structure by calculating the spin orbit coupling and magnetic dipole dipole interaction energies. The calculated exchanges correctly predict the observed magnetic structure below 52 K, and lead practically to no spin frustration. The perpendicular to c- and parallel to c-spin orientations are predicted by the spin orbit coupling and the magnetic dipole dipole interactions, respectively. However, the magnetic dipole dipole interactions are stronger than the spin orbit coupling interactions, and hence are responsible for the spin orientation observed for Ni3TeO6.