Hi Sanir,
Thanks for using Syncfusion Products.
Since our WPF Docking Manager is not an items control and it is not possible to acheive the MVVM pattern by normal way.But this can be acheived by creating an adapter or wrapper for the Docking Manager.
Could you please refer the below article to acheive the MVVM pattern in Docking Manager.
http://www.syncfusion.com/blogs/post/MVVM-Adapter-for-WPF-Docking-Manager.aspx
Please let us know if you have any queries.
Regards,
Muthalagu