Hello Mohammed,
Assuming you have SSL Server PSE and SSL Client PSE setup and are trusted by your company CA, your company CA will then need to issue a user certificate for the user that you wish to login into SAP with ( I assume this will be your AD userid) .
This user certificate will need to be imported into your browser and some additional steps on ABAP to ensure it recognizes the user certificate when presented by the browser.
Check the following blog for pointers.
Enabling X.509 based SSO for the SAP Web AS ABAP with your own CA based on OpenSSL for Windows
Regards,
Siddhesh