Hello Mohit,
The SAP Single Sign-On product requires license. Once your company purchase the product you will be able to see and download the product from the SAP Service Marketplace.
For more details, see the SAP Note: 1876552 - Cannot find SAP Netweaver Single Sign-On 1.0 (NWSSO1.0) or SAP Single Sign-On 2.0 (SSO2.0) products to download from the SAP Service Marketplace
Regards,
Donka Dimitrova