SQL Server 2012 supports upgrading from the following earlier editions of Reporting Services:
SQL Server 2005 SP4 Reporting Services
SQL Server 2008 SP2 Reporting Services
SQL Server 2008 R2 SP1 Reporting Services
You can choose to perform an in-place upgrade or migrate a Reporting Services Installation to SQL Server 2012. You can run the Upgrade Advisor tool on the Report Server computer to determine any issues that ...