If its AEM 5.6.1 and both are clustered than no need to manually replicate. and If you are not seeing the changes in another instance then something is wrong, take a look at whether they are clustered or not, http://<host/port>/libs/granite/cluster/content/admin.html
if the publish instances are clustered, you would not need to replicate from one instance to another. The content should be synchronized internally across all the instances in the cluster.
If its AEM 5.6.1 and both are clustered than no need to manually replicate. and If you are not seeing the changes in another instance then something is wrong, take a look at whether they are clustered or not, http://<host/port>/libs/granite/cluster/content/admin.html