Upgrading to opendistro from elasticsearch

I am trying to upgrade from elasticsearch 6.8 to opendistro 1.6.0
I’m following cluster restart upgrade steps
but after starting elasticsearch when trying to query elastic search for nodes its says
Open Distro Security not initialized.
Then I try to enable security by running the securityadmin.sh script
Script is able to connect to cluster but Im getting following error:

Elasticsearch Version: 7.6.1
Open Distro Security Version: 1.6.0.0
Diagnostic trace written to: /etc/elasticsearch/securityadmin_diag_trace_2020-May-28_14-36-26.txt
Contacting elasticsearch cluster 'elasticsearch' ...
Clustername:test6x
Clusterstate: RED
Number of nodes: 5
Number of data nodes: 2
.opendistro_security index already exists, so we do not need to create one.
ERR: .opendistro_security index state is RED.
Populate config from /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/
Will update '_doc/config' with /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/config.yml
   FAIL: Configuration for 'config' failed because of UnavailableShardsException[[.opendistro_security][0] primary shard is not active Timeout: [1m],

Can someone let me know how to proceed.