Hello Gaurav Mehta,
From you are saying about the RadGrid and the dynamic control you want to create I do not see any problems with it. Once again I suggest using of custom control.
1) Sitefinity site bin folder file version : 2009.1.410.35
You use Q1 2009 dll for .NET Framework 3.5. This means you use not the last version of Sitefinity . Most probably you use Sitefinity 3.6
2) Latest version file (on telerik site - available for download) : 2009.3.1208.20
You need to download the latest version from Telerik.com and then create a bindingRedirection
in your web.config file. Note that upgrades of the controls are not recommeded due to internal dependencies with the other Sitefinity's assemblies. You can use probing path element to avoid any troubles.
the Telerik team