When you use Sangan as a tribute can you activate it's effect?
Yes, Sangan has a Mandatory Trigger (so never misses the
timing), and a tribute is a form of Send.
If you tribute it for a tribute summon, Sangan will activate
when the summon is successful, or if the summon is negated, after
the resolution of the negation card.
If you tribute it for a card effect such as Enemy Controller,
then allow the chain to resolve. Sangan will start a new chain as
chain link 1.