@Santhosh Kumar r - there are some free options on the Atlassian Marketplace here: https://marketplace.atlassian.com/search?hosting=server&moreFilters=free&product=confluence&query=sso
If you already have a user directory, you can configure LDAP using this walkthrough: https://confluence.atlassian.com/doc/connecting-to-an-ldap-directory-229838241.html - please note the version of Confluence in the upper right may need to be changed depending on what you need.
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event