Hi Imran,
Thank you for your interest in Essential Studio.
Adobe XFA forms are also treated like the normal Acroforms.You can use the same API to read and fill Adobe XFA forms.Please refer the documentation for form filling in the below link.
Documentation Link:
http://help.syncfusion.com/ug_81/Reporting_PDF/FormFilling.htmlPlease let us know if you have any queries.
Regards,
Angappan.