>1. How to place controls (Combo,ChkBox) in Grid Columns?
>

Here is a link that explains about using a combobox and how to use a checkbox:

http://www.syncfusion.com/FAQ/WinForms/FAQ_c44c.asp#q480q


>2. Same with its Child grid having mater child relation.
>

Here is a link that explains how to set up both grids and the relationship

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vbcon/html/vbtskcreatingmasterdetailslistwithdatagrid.asp


>3. What event is fired when new row is added in grid?
>

The event to look at is the RowChanged event of the DataTable class. You can check the Action property to find out what kind of change occured and check for Add.


>4. What event is fired when focus is on Child grid in side Grid?
>

There is an event called Enter for the DataGrid. You could use that event to determine when the user entered the child grid.

>TIA
>
>Diptesh