When requesting a Custom Object, use the requestJSON to pass the Custom Object data, and the response will have responseJSON which stores the Custom Objects response returned by NetSuite.
The Custom object has the following parameters.
Read-Only field, provides the Salesforce Record ID upon successful creation or updation in Salesforce.
Custom fields and their values.
Internal ID of the Custom Form.
Internal ID of the Custom Object.
Unique ID that NetSuite holds. It is required during the update of a Record.