  We have studied the $CP$ violation discovery reach in neutrino oscillation
experiment with superbeam in presence of non-standard interactions of neutrinos
with matter for both short and long baselines. For the most important channel
of oscillation ($\nu_\mu \rightarrow \nu_e$) for $CP$ violation discovery there
is significant effect in the oscillation probability particularly due to NSIs'
$\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$ for longer baseline and higher
energy in comparison to other NSIs'. Interestingly for these two NSIs' (for
real and higher allowed values) there is possibility of better discovery reach
of $CP$ violation than that with only Standard Model interactions of neutrinos
with matter provided that NSI values are known. For complex NSIs' we have shown
the $CP$ violation discovery reach in the plane of Dirac phase $\delta$ and NSI
phase $\phi_{ij}$. Our analysis indicates that for some values of some NSI
phases total $CP$ violation may not be observable for any values of $\delta $.
