We present our results of tau neutrino events analysis at the Iron Calorimeter detector in the proposed India based Neutrino Observatory. The charged current $\nu_\tau$ events at the detector cannot be separated from the neutral current events of all flavors. Hence, we have analyzed the combined charged current and neutral current events. The event samples were prepared with the NUANCE event generator. By simulating a data taking period of 10 years, we have shown that the detection capability for tau neutrino events is over 3 sigma confidence level. We performed the sensitivity study of $\nu_\tau$ to the oscillation parameters $\theta_{23}$ and $\Delta m^2_{32}$. We also performed the combined analysis of $\nu_\tau$ events and $\nu_\mu$ events and that study shows that we can expect a significant improvement in sensitivity to the oscillation parameter $\theta_{23}$ and its octant, and a moderate improvement in $\Delta m^2_{32}$ comparing to the standard muon analysis.