  In this paper we study the synergy among the future accelerator (T2HK),
future atmospheric (ICAL) and future reactor (JUNO) neutrino experiments to
determine the neutrino mass ordering. T2HK can measure the mass ordering only
for favorable values of $\delta_{\rm CP}$, whereas the mass ordering
sensitivity of JUNO is dependent on the energy resolution. Our results show
that with a combination of T2HK, ICAL and JUNO one can have a mass ordering
sensitivity of 7.2 $\sigma$ even for the unfavorable value of $\delta_{\rm CP}
= 0^\circ$ for T2HK and most conservative value of JUNO energy resolution of
5$\%/\sqrt{E(MeV)}$. The synergy mainly comes because different oscillation
channels prefer different values of $|\Delta m_{31}^2|$ in the fit when the
mass-ordering $\chi^2$ is minimized. In this context we also study: (i) effect
of varying energy resolution of JUNO, (ii) the effect of longer run-time of
ICAL, (iii) effect of different true values of $\theta_{23}$ and (iv) effect of
octant degeneracy in the determination of neutrino mass ordering.
