Depends on how you configure and use your cache. E.g., if you use synchronous replication or wrap the calls in a transaction (or both) you'd pretty much guarantee that the other instances see it in the same order.
So, but in the case of synchronous communication if my two instructions arrive from different hosts Ex:
C1.put("/a/b", "Key1", "1");
C1.put("/a/b", "Key1", "2");
Can we guarantee that we are going to receive booth messages in the same order in all hosts?
If they are from different hosts, then no. We don't acquire a cluster-wide lock when you invoke the call.