  An analysis is given of the decay $\tau \to \mu+ \gamma$ in MSSM extensions
with a vector like generation. Here mixing with the mirrors allows the
possibility of this decay. The analysis is done at one loop with the exchange
of charginos and neutralinos and of sleptons and mirror sleptons in the loops.
It is shown that a branching ratio ${\cal B}(\tau\to \mu+\gamma)$ in the range
$4.4\times 10^{-8} -10^{-9}$ can be gotten which would be accessible to
improved experiment such as at SuperB factories for this decay. The effects of
CP violation on this decay are also analyzed.
