How to insert Group by data from old Data table to a new table?

Hi @Jolin,
As I understand that you are going to remove the duplicates . In that case you can use the DefaultView from Datatable like below.

dtNew=dt.DefaultView.ToTable(True,“Column1”,“Column2”,“Column3”,“Column4”) [Specific columns]
or
dtNew=dt.DefaultView.ToTable(True) [All the columns]

Regards
Balamurugan