As specified in this Link
We need to copy the node certificate to the appropriate locations.
Copy the applicable .p12 file into a directory within the Elasticsearch configuration directory on each node. For example, /home/es/config/certs. There is no need to copy the CA file to this directory.
Thanks in advance
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FOUND it:
Its in /etc/elasticsearch directory
The older version's directory structure helped:
https://www.elastic.co/guide/en/elasticsearch/reference/2.3/setup-dir-layout.html