Hello @Devendra_Bhardwaj ,
For the instruction to change the column name, please use an assign activity (https://docs.uipath.com/studio/docs/the-assign-activity ) not an Write Line activity.
To check you can use this sequence:
Write line: yourDT.Columns(0).ColumnName
Assign: yourDT.Columns(0).ColumnName = “New Column Name”
Write line: yourDT.Columns(0).ColumnName
Carefully check again Paul’s solution:
Best regards,
Marius