Hi Hemant,
Sorry for the delayed response.
i) When the docking window is resized, the size of the usercontrol is changed automicatically to fit the docking window. You need not change it explicitly.
ii) If you dock the window to Left or Right of the form, the docking window should fit into the form''s height automatically when resized. Similarly, if it is docked to the Top or Bottom, it will fit into the width of the form automatically when resized.
Please let me know if I am misunderstood your requirement. And also if possible, could you please modify the sample attached to reproduce the problem? It will help us resolve this issue accurately.
Thanks for your interest in Syncfusion products.
Regards,
Vijay
Test Sample