  We quantitatively study the percentage of fake events present in CCQE and
CCRes interactions and the impact of final state interactions on the neutrino
oscillation parameters at Dune. Resonance interaction will be the most dominant
interaction in the oscillation sensitive region of DUNE. The effect of
final-state interactions for DUNE oscillation physics is analysed in an ideal
and realistic detector scenario. The $\nu_{\mu}$-disappearance Oscillation
channel is studied using LAr detector. We find that nuclear effects and
detector thresholds plays an significant role in CCQE and CCRes interactions
and these nuclear effects induces a significant bias in the determination of
atmospheric oscillation parameters. The impression of nuclear effects on the
determination of $\theta_{23}$ is quantified in this work.
