  In the present work, we have considered minimal unitarity violation(MUV)
scheme, to obtain the general expression for $\nu_{\mu}\rightarrow\nu_{\tau}$
oscillation probability, in vacuum. For this channel, we have investigated the
sensitivities to non-unitary parameters $|\rho_{\mu\tau}|$ and
$\omega_{\mu\tau}$ with short baseline(SBL) experiments for normal as well as
inverted hierarchical neutrino masses. We also check how the sensitivity to
non-unitary parameters get modified for $\theta_{23}$ above and below
maximality. We find that the $3\sigma$ sensitivity towards $|\rho_{\mu\tau}|$
is maximum for non-unitary phase $\omega_{\mu\tau}=0$, whereas it is minimum
for $\omega_{\mu\tau}=\pm\pi$ in case of normal hierarchy(NH). However, the
sensitivity is minimum at $\omega_{\mu\tau}=0$ and maximum for
$\omega_{\mu\tau}=\pm\pi$ for inverted hierarchy(IH). We observe that for
unitary $CP$ phase $\delta=0$ and $\delta=\pi/2$, the sensitivity to measure
non-unitarity remains same in both the cases. We, also, explore wide range of
$L/E$ to forecast, in principle, the possibilities to observe $CP$-violation
due to unitary($\delta$) and non-unitary($\omega_{\mu\tau}$) phases. We find
that the both phases can be disentangled, in principle, from each other, for
the $L/E$ range less than 200 km/GeV for $\nu_{\mu}\rightarrow\nu_{\tau}$
channel.
