You can use the below LINQ Expression to replace the yes with pending in specified 3 column,
- Assign -> dt_Output = (From row In dt_Input.AsEnumerable
Let Column3Value = If(row("Column3").toString.tolower.equals("yes"), "pending", row("Column3").ToString)
Let Column4Value = If(row("Column4").toString.tolower.equals("yes"), "pending", row("Column4").ToString)
Let Column5Value = If(row("Column5").toString.tolower.equals("yes"), "pending", row("Column5").ToString)
Select dt_Input.Clone.Rows.Add(row("Column1"), row("Column2"), Column3Value,Column4Value, Column5Value)
).Copytodatatable()
Note: Change the column names based on your input data.
Hope it helps!!