  During the run III of the LHC, the forward experiments FASER$\nu$ and SND@LHC
will be able to detect the Charged Current (CC) interactions of the high energy
neutrinos of all three flavors produced at the ATLAS Interaction Point (IP).
This opportunity may unravel mysteries of the third generation leptons. We
build three models that can lead to a tau excess at these detectors through the
following Lepton Flavor Violating (LFV) beyond Standard Model (SM) processes:
(1) $\pi^+ \to \mu^+ \nu_\tau$; (2) $\pi^+ \to \mu^+ \bar{\nu}_\tau$ and (3)
$\nu_e+{\rm nucleus}\to \tau +X$. We comment on the possibility of solving the
$(g-2)_\mu$ anomaly and the $\tau$ decay anomalies within these models. We
study the potential of the forward experiments to discover the $\tau$ excess or
to constrain these models in case of no excess. We then compare the reach of
the forward experiments with that of the previous as well as next generation
experiments such as DUNE. We also discuss how the upgrade of FASER$\nu$ can
distinguish between these models by studying the energy spectrum of the tau.
