Problem resolved. Support identified an invalid PAY package body. It had hard coded "apps" in the script. We are not APPS. Corrected the package and then worked.
Please contact Mr V K Sharma at Alpha Techsolutions Private Limited , his email is firstname.lastname@example.org.We had several issues in ERP and his solutions have worked perfectly. Now we are facing issues with GST and Fixed Assets Module and he along with his Team is supporting all our Returns and Support.
My sincere advice is to take support from his organization for any ERP issues faced by your Organisation whether GL, AP, AR, FA Cash Management , PO & Inv or GST taxes.
Thanks & Regards