As of Q2 2013 Telerik Reporting is built against .NET4 supported by Visual studio 2010+ version.
The last version with support for earlier .NET frameworks is Telerik Reporting Q1 2013 SP1
(there is an internal build as well). If you use this account, you can download the product version after logging into your account and navigating to Products & Subscriptions - DevCraft Complete - Download - Reporting - Older versions - 22.214.171.1246
Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.