Garuda: All autoattacks, Downstream, Wicked Wheel.
Ramuh: Literally nothing is parryable.
Rafflesia: Everything Rafflesia targets just the Tank with except for Swarm is parryable. Leafstorm, Bouquet, and Spit cannot be parried.

In general: If the boss is directly targeting the Tank with an attack, there's a very high chance that it is physical. Fights like Ramuh are the exception, not the rule.