Hi Shouvik,
The virtual mode is available in grouping grid. This can be achieved by enabling EngineOptimization technique. Please refer to our shipped browser sample ‘EngineOptimizations‘ ( \\windows\Grid.Grouping.Windows\Samples\EngineOptimizations ) for more details. The VirtualMode optimization can be achieved when there are no SortedColumns, RecordFilters, GroupedColumns and no nested relations for a table, then virtual mode can be used.
In addition to that you could fill the innermost tables on demand only when the user expands the nested table.
Please refer this thread:
http://www.syncfusion.com/Support/Forums/message.aspx?MessageID=28180Best Regards,
Haneef