Hello Vinod,
Thanks for your interest in Syncfusion products.
I have tried your condition that you have mentioned here in the Grid.Windows\Samples\2.0\DataBound\GDBGwithDropGrids sample by including the code snippet that you have sent for the child grid. And I was not able to reproduce the issue. The child grid gets resized without any problem.
I have attached the sample that I have used for testing with this post. You can get the sample in the following link -
http://websamples.syncfusion.com/samples/Grid.Windows/F67352/main.htmI am also sending you the video clip for your reference -
http://www.syncfusion.com/Support/user/uploads/F67352_f6cc1092.zip. Please look into the above details and modify the sample to reproduce the issue if you still finds any issue with this. Dont hesitate to contact us if you have any questions. We will be glad to assist you.
Best Regards,
Meera.
Syncfusion, Inc.
http://www.syncfusion.com/