Hello Krish,
You can use SAML technology only for SAP GUI for HTML. If you want to implement SSO for scenarios that include SAP GUI for Windows, you need to have a solution that supports SNC with Kerberos or X.509 Client Certificates. The SAP Single Sign-On product (license required) supports both technologies and also could help you to implement "One login" for your SAP GUI scenarios if the primary authentication service for your company is SAML based.
See the details here:
What Is Secure Login? - SAP Library
Here are the details how to do the user mappings User Mapping - What Is Secure Login? - SAP Library
Regards,
Donka Dimitrova