the only option is to go to a court and file a civil suit against anyone that could potentially handle your coins in the future.
this means listing the addresses the coins moved to and any info you have on the people that scammed you. and listing a bunch of exchanges that you think could be used to filter/convert your funds through.
and then serve the exchanges with the court order.

but for a loss of just $6k this is not an economical tactic.

final option is as others already said. take any and all info you have on the scammer, (contact info) and report it to the police. and HOPE that there could be found some trace of the scammers identity if the police raise it up to the cyber crimes departments that have connections with ISP's and other communication services. but thats a HOPE

the learning experience from this is to never hand any funds to anyone unless you know enough about them to slap them with a wet fish or a court order directly if they abuse you. .. after all would you hand a stranger that passes you on the street a suitcase of $6k without even knowing their name