  The main aim of the T2K experiment in Japan is to discover CP violation in
the leptonic sector by measuring the Dirac phase $\delta_{CP}$. For that
purpose T2K has already started collecting data in both neutrino and
antineutrino mode. But in this work we will show that, in T2K the main role of
the antineutrinos is to resolve the octant degeneracy. If the octant is known
then the pure neutrino run of T2K is capable to give the maximum CP
sensitivity. On the other hand in the experiment like NO$\nu$A, antineutrinos
are still useful even when octant is known. Thus we propose that let T2K run in
the dominant neutrino mode whereas the antineutrino component of the other
experiments can resolve the octant degeneracy in T2K. As an example we show
that if T2K is combined with the experiments NO$\nu$A and ICAL@INO, then T2K
will have the potential to discover CP violation with maximum sensitivity in
the dominant neutrino mode.
