  The tau lepton plays important role in distinguishing neutrino mass patterns
and determining the chirality nature in heavy scalar mediated neutrino mass
models, in the light of the neutrino oscillation experiments and its
polarization measurement. We investigate the lepton flavor signatures with tau
lepton at LHC upgrades, i.e. HL-LHC, HE-LHC and FCC-hh, through leptonic
processes from doubly charged Higgs in the Type II Seesaw. We find that for the
channel with one tau lepton in final states, the accessible doubly charged
Higgs mass at HL-LHC can reach 655 GeV and 695 GeV for the neutrino mass
patterns of normal hierarchy (NH) and inverted hierarchy (IH) respectively,
with the luminosity of 3000 fb$^{-1}$. Higher masses, 975-1930 GeV for NH and
1035-2070 GeV for IH, can be achieved at HE-LHC and FCC-hh.
