Magneto-tunneling studies in a high-quality InGaAs/AlAs/GaAs triple well structure in a tilted magnetic field are reported. Well-defined structures in the I(V) characteristic in the resonance regime are observed which correspond to tunneling from Landau levels in the prewell into the midwell with nonconservation of the Landau-level index tunneling transitions. These tunneling transitions with Δn both positive and negative are observed for the first time in the resonant regime under tilted magnetic field. Finally, the results are shown to be in fair agreement with a coherent magneto-tunneling model where the effect of the transverse component of the magnetic field is treated as a perturbation.