Find Missing Data From Parent Table?

SELECT c.table_name CHILD_TABLE, p.table_name PARENT_TABLE
FROM user_constraints p, user_constraints c
WHERE (p.constraint_type = 'P' OR p.constraint_type = 'U')
AND c.constraint_type = 'R'
AND p.constraint_name = c.r_constraint_name
AND c.table_name = UPPER('ODS_TSAF_MES_PC');

and output is

child table parent table
ODS_TSAF_MES_PC ODS_TSAF_MES_PCTYP
ODS_TSAF_MES_PC ODS_TSAF_MES_PC
ODS_TSAF_MES_PC ODS_TSAF_MES_PCSTAT

i tried

SELECT A.piecestatus from ods_TSAF_MES_PCSTAT A WHERE NOT EXISTS
(SELECT * FROM ODS_TSAF_MES_PC B WHERE B.piecestatus = A.piecestatus);

and i found one piecestatus values is 'I' but i am not getting where it is related to the table and in which row it is getting affected?