Hi @nanda_kishore !
you can find the unique values by invoking the following LINQ expression:
var_InputFile.AsEnumerable.Select(Function(a) a("Description").ToString).Distinct.ToList().Where(Function(b) Not String.IsNullOrWhiteSpace(b)).ToArray
this will retunr a list of all the values, without the duplicates. Since then you want to identify of those, the ones that are repeated, what you can do is apply a ForEach Unique Description, and if it has more than 1 match on the original DT, you then know that the result is a duplicated row.
Just for demo purposes, on the example attached, the duplicated values are saved in a list of strings, so then you can Lookup Them on the DT (With the “Lookup Data Table” activity), and delete that row from the original DT. ending with a clean DataTable.
DuplicateRowsCount.zip (44.6 KB)
Hope it helps!