This can be done only after adding domain to the netsuite account and then we have to copy the CNAME generated while adding the domain:
- Sign in again into https://my.freenom.com/
- Go to my domains section and there you can see your purchased domains.

- Click on the manage domain option.

- Type the www in the Name section
- Select the Type as ‘CNAME’ (CNAME can be get from while adding the same domain into Netsuite account)
- paste the caname copied from domain setup on netsuite to the Target coloumn.
- TTL section value is 3600 as default if we reduce to 1000 or any value, it will reduce the DNS activation time.
- Then click save changes and DNS will activate after few minutes.