Hello Kanika
Can you please confirm your EA-HRCIN support patch level?
Ideally if your EA-HRCIN System release level is 605, as this is a mandatory requirement , as SAP note
1393999 - Customer Specific Text / Global ID / Employee No. on Form 16 is the solution is available from EHP-5 Release only.
Please check on this and confirm.
Thanks and Kind Regards
Ramana