SCOTT@dws>select * from t2;

COL1
--------------------
Ram Kumar
RamKumar
Rm Kumar
Ram
Ram Kumar

Elapsed: 00:00:00.67
SCOTT@dws>select replace(col1,' ') col1, count(replace(col1,' ')) cnt
  2  from t2
  3  group by replace(col1,' ');

COL1                        CNT
-------------------- ----------
RmKumar                       1
RamKumar                      3
Ram                           1

SQL> WITH datas AS
  2  (
  3  SELECT 'ramkumar' AS s1, 'ram kumar' AS s2 FROM dual union ALL
  4  SELECT 'Waldar'                    , 'Walder'                       FROM dual union ALL
  5  SELECT 'Perfect match'             , 'Perfect match'                FROM dual union ALL
  6  SELECT 'Awful match'               , 'Bad similitude'               FROM dual
  7  )
  8  SELECT s1, s2,utl_match.jaro_winkler(s1, s2)
  9    FROM datas
 10   WHERE  utl_match.jaro_winkler(s1, s2)> 0.96;

S1            S2             UTL_MATCH.JARO_WINKLER(S1,S2)
------------- -------------- -----------------------------
ramkumar      ram kumar                         9.741E-001
Perfect match Perfect match                       1.0E+000

SCOTT@orcl_11gR2> SELECT * FROM employee ORDER BY empname
  2  /

EMPNAME
---------------
kumar
ram
ram kumar
ramkumar
rm kumar

5 rows selected.

SCOTT@orcl_11gR2> SELECT empname duplicate_names
  2  FROM   (SELECT empname,
  3  		    COUNT (*) OVER (PARTITION BY REPLACE (empname, ' ', '')) cnt
  4  	     FROM   employee)
  5  WHERE  cnt > 1
  6  /

DUPLICATE_NAMES
---------------
ramkumar
ram kumar

2 rows selected.

SCOTT@orcl_11gR2>