Hi Veron,
Sorry about the inconvenience caused.
As mentioned earlier, ASP.NET MVC controls are usually HtmlExtensions and they do not appear on the Toolbox for use on a design surface. Since we have launched newer set of ASP.NET MVC controls powered by javascript, we have marked older MVC controls prior to our release 12.1 as MVC Classic.
Adding the Syncfusion ASP.NET MVC Classic Tools product to your application - http://help.syncfusion.com/ug/asp.net%20mvc/documents/howtoaddessentialtoo.htm
Complete documentation for all our products - http://syncfusion.com/library
Please let us know if you require further assistance.
Regards,
Ezhil S