I am glad you contacted us.
To select the last added row and edit it, first you need to subscribe to the UserAddedRow event, which will trigger after the row has already been added to the collection of rows, which on the other hand will allow us to easily access the last element in that collection. Please see the code below:
I hope this helps.
Off topic, you have posted the same thread in the ChartView section. Due to duplicity the other thread is deleted.
sender, Telerik.WinControls.UI.GridViewRowEventArgs e)
.radGridView1.ChildRows.Count - 1;