Hi Prasad,
Unfortunately, TestComplete doesn't provide any extended methods and properties for automating Flex AdvancedDataGrid, but you might be able to perform the needed actions with the grid's native methods and properties. You can access these native methods and properties in the Object Spy and your tests via the grid's FlexObject property. To see an example of how the native methods are used in tests, please refer to the Work with AdvancedDataGrid How To entry.
BTW, you can submit a feature request for the extended AdvancedDataGrid support here, and if it gets enough votes, the TestComplete team will consider adding it to the roadmap for future versions.
I hope this information helps :)
