Hello @srikanthtns,
If you request a trial license, you will receive a 30-day Mattermost Enterprise Edition E20 Trial License which will include all Enterprise features, including SAML. Once SAML is enabled in the System Console, your users can create an account with SAML, or switch their existing account to SAML from Account Settings > Security > Sign-in Method.
As for generating the xml file - do you mean the file used to set up encryption? If so, you can generate the encryption files using the scripts here.