Currently, the position and size of the merged cell can be fetched via the numeric position and length properties of the MergedCellInfo class. This allows you to implement custom code that iterates the Columns collection of RadGridView and extractс the parent GridViewColumn(s).

Add a property that allows you to get the columns hosting the merged cell. The property should be able to get a single column (when the cells are merged vertically) and multiple columns when (when merged horizontally).