Dear Lakshmana,
You might used different structures in the IMPORT and EXPORT which causes the mismatch between exporting and importing parameter.
If it is in a standard search for SAP note with CX_SY_IMPORT_MISMATCH_ERROR and you will get result notes explaining those.
Since it seems to be a Z* program correct the declaration of both the structures in IMPORT and EXPORT and check.
Regards,
Thanga