In this work, we study the magneto transport properties of two III nitride systems which are expected to be the work-bench for relevant spin dependent phenomena. These two systems are GaN with embedded GaxFe4xN nanocrystals (GaN-NC) and degenerated InxGax1N:Si. Both systems are fabricated by metal organic vapour phase epitaxy. The magneto transport measurements are performed at temperatures down to 1.59 K and magnetic fields of up to 6.9 T. For the GaN-NC system a clear influence of the nanocrystals on the transport properties is observed. However, the measurements do not show a clear evidence for spin polarisation effects. The magneto transport measurements for the InxGax1N:Si system shows the onset of weak anti localisation, which indicates InxGax1N:Si to be a Rashba semiconductor. In order to quantify the Rashba coupling parameter the crystalline quality in the InxGax1N:Si layer needs to be improved, aiming to increase the carrier mean free path.