Hi,
  
 We have already setup single sign on in our orgnisation which uses saml 1.1, what are the steps 
I have to make to setup in sharepoint 2013 webapplication  to have single sign on enabled.

Regards,
Patil

1. Establish a trust relationship between the IP and Relying Party 
2. Export the trusted Identity Provider certificate
3. Create a new SharePoint Web application and configure it to use SAML sign-in

Refer to the following article for more information

https://technet.microsoft.com/en-us/library/ff607753%28v=office.14%29.aspx?f=255&MSPPError=-2147217396