Lifecycle policy to a different cluster

I would like to maintain data 6 month on my main elasticsearch cluster. Then I would like to apply a lifecycle policy to move indexes to a DIFFERENT cluster. I can't use the same cluster because of security and compliance rules... Is it possible? How can I do that?

Thank you in advance for your help

ILM does not support moving indices to a different cluster. You could create periodic snapshots and move data across that way or use cross-cluster replication to move data across in real time.

I would like some further clarification:
I need to replicate just indexes older than 6 months. is it possible to dynamically select them using either periodic snapshots or cross-cluster replication?
Real time replication is not required, I want to move just read-only indexes...
If I choose the snapshot solution, I need to copy data on a temporary repository and then move data to the second cluster, correct?