[elasticsearch] How to know elastic search installed version from kibana?

The user @manoj has provided the correct answer to the question. From Kibana host, a request to http://localhost:9200/ will not be answered, unless ElasticSearch is also running on the same node. Kibana listens on port 5601 not 9200.

In most cases, except for DEV, ElasticSearch will not be on the same node as Kibana, for a number of reasons. Therefore, to get information about your ElasticSearch from Kibana, you should select the "Dev Tools" tab on the left and in the console issue the command: GET /