I have added a rad grid, and added a property AllowMultiRowSelection="true".
In my case I want to select the row onclick event of row and again click of the same row it should be deselect at client side.
In current situation it does not happen it can not deselect the selected row.
I have found the following forum link which discusses a similar requirement. Go through it and see whether it helps. how to deselect a row in the radgrid