  The long-baseline experiment T2K in Japan has collected data in the neutrino
mode corresponding to an exposure of $6.57 \times 10^{20}$ POT (Protons on
Target) and currently it is running in the antineutrino mode. The main aim of
the antineutrino run is to measure the leptonic phase $\delta_{CP}$ which may
help to understand the matter-antimatter asymmetry of the universe. In this
work we show that in T2K, antineutrinos are required only for removing the
wrong octant solutions which in turn improves the CP sensitivity. If however
the octant is known then pure neutrino run is capable of giving the maximum CP
sensitivity. If we divide the total true parameter space into eight sets, then
we find that T2K antineutrino run helps in improving the CP sensitivity for
only two sets while for the remaining six combinations pure neutrino run gives
the best CP sensitivity. Thus if the neutrino run is replaced by the
antineutrino run then it causes a reduction in the CP sensitivity in 75$\%$ of
the true parameter space due to lesser statistics. Thus it is worthwhile to
study if the T2K antineutrino run can be reduced by the antineutrino runs of
the other experiments, so that T2K can run in dominant neutrino mode to extract
the best CP sensitivity. In this work we explore the possibility of the
antineutrino component of NO$\nu$A and the atmospheric neutrino experiment
ICAL@INO for compensating the antineutrino run of T2K.
