How to change the DataTable Column Name?

 dtTempColumn.Columns["EXCELCOLUMNS"].ColumnName = "COLUMN_NAME";                        
 dtTempColumn.AcceptChanges();

Rename the Column by doing the following:

dataTable.Columns["ColumnName"].ColumnName = "newColumnName";

Use:

dt.Columns["Name"].ColumnName = "xyz";
dt.AcceptChanges();

or

dt.Columns[0].ColumnName = "xyz";
dt.AcceptChanges();

Try this:

dataTable.Columns["Marks"].ColumnName = "SubjectMarks";