So Tusken let's you discard a card after activation to resolve ONE of its dice. I roll special of Holocron, choose to discard, resolve Sith Holocron, put down Mind Probe, pay 1 to roll its die into dice pool. Roll special, can I resolve the Mind Probe special or do I have to wait a turn?

No. You weren't doing a resolve dice action on specials. You were using the Raiders ability to resolve one die, so you only get to resolve one die.