Hello All, I'm trying to insert contains fields of the List/Record type , where can I find the Internal Ids of those records,

To enable the Show Internal IDs preference: 1. Go to Home > Set Preferences. The General subtab is displayed by default. 2. In the Defaults section, click Show Internal IDs. When this preference is enabled: • You can view the internal ID for a field by clicking on that field's label to open the field level help popup window. The internal ID is displayed in the lower right corner of this window. • You can view the internal ID for a record or a custom field in an Internal ID column that displays on a list or search results page for that type of record or custom field. • You can view the internal IDs for workflow actions on the workflow context panel, workflow action group window, and sublist action group window. You can also view internal IDs in workflow execution logs.

To add to Katrina's suggestion, I also use the Schema & Record browser a lot. Please note, this website does not include any custom fields or record types: https://www.netsuite.com/help/helpcenter/en_US/srbrowser/Browser2017_1/schema/record/account.html

There is also an Advanced Field Help chrome plugin that can give you even more details when clicking on field labels.

Is the Advanced Filed Help chrome plug in free?

Yes