Elastic Search is not assigning index to all the nodes in the cluster

Hi,
I have a 6 node ES cluster. When a new index is created it is assigning to only two nodes..Is there any setting I need to set to even distribution of shards of each index along all the nodes....

Thanks.

I think you are searching for the number of primary shards option (given that you have replicas, you may want to set this to half of your nodes). See https://www.elastic.co/guide/en/elasticsearch/reference/7.6/index-modules.html#_static_index_settings