RAVANJU
RAVUNAJ
NUVAJAR
AAURNVJ
UAVARJN

CREATE OR REPLACE TYPE t_chr1_tab as table of varchar2(1);
/

CREATE OR REPLACE FUNCTION split_str( p_str IN VARCHAR2 )RETURN t_chr1_tab 
AS
   l_str LONG 
   DEFAULT p_str;
   l_n NUMBER := 1;
   tab1 t_chr1_tab := t_chr1_tab();
BEGIN
   IF LENGTH(p_str) > 0 
   THEN
      -- get individual characters into table
      FOR i IN 1..LENGTH(p_str)
      LOOP
         tab1.extend;
         tab1( tab1.count ) := SUBSTR(l_str, i, 1);
      END LOOP;

   END IF;

   RETURN tab1;
END;
/

Connected to:
Oracle Database 10g Enterprise Edition Release 10.2.0.3.0 - 64bit Production
With the Partitioning, OLAP and Data Mining options

SQL> with x as(select letter, rnd, len, rownum rn
  2              from (select column_value letter, dbms_random.value rnd,
  3                          count(*) over(PARTITION BY 1) len
  4                      from TABLE( split_str('RAVANJU' ) )
  5                      order by 2))
  6  select replace(sys_connect_by_path(letter, ','), ',', '') str1
  7      from x
  8    where rn=len
  9    start with rn=1
 10    connect by prior rn = rn-1;

STR1
--------------------------------------------------------------------------------
UJNVRAA

SQL> /

STR1
--------------------------------------------------------------------------------
AAJRNUV

SQL> /

STR1
--------------------------------------------------------------------------------
RNJUAAV

SQL> /

STR1
--------------------------------------------------------------------------------
RUNAAVJ

SQL> /

STR1
--------------------------------------------------------------------------------
ARAVNJU

SQL>

SQL> SELECT  REPLACE(SYS_CONNECT_BY_PATH (NM1, '/'),'/') RESHUFF_NAME
  2  FROM    (SELECT X.NM1, LEN, ROWNUM R1
  3                FROM (WITH REC AS (SELECT 'ANDREW' NM FROM DUAL)
  4                      SELECT  SUBSTR (NM, ROWNUM, 1) NM1,
  5                              LENGTH (NM) LEN,
  6                              DBMS_RANDOM.VALUE (1, 2)
  7                      FROM REC
  8                      CONNECT BY LEVEL <= LENGTH (NM)
  9                      ORDER BY 3
 10                      ) X
 11          )
 12  WHERE R1 = LEN
 13  START WITH R1 = 1
 14  CONNECT BY R1 = PRIOR R1 + 1;

RESHUFF_NAME
---------------
ANWEDA

SQL> /

RESHUFF_NAME
---------------
RNADER

SQL> /

RESHUFF_NAME
---------------
DRWNAE

SQL> /

RESHUFF_NAME
---------------
DREAWN

SQL> /

RESHUFF_NAME
---------------
NRDEAN

SQL>

SQL> WITH T AS
  2       (SELECT 'ANDREW' STR
  3          FROM DUAL)
  4  SELECT  SUBSTR (STR, LEN1 + 1) || REVERSE (SUBSTR (STR, 1, LEN1)) STR1
  5            FROM (SELECT STR, LENGTH (STR) L,
  6                         ROUND (DBMS_RANDOM.VALUE (0, LENGTH (STR))) LEN1
  7                    FROM T)
  8  ;

STR1
------------
WERDNA

SQL> /

STR1
------------
REWDNA

SQL> /

STR1
------------
WERDNA

SQL> /

STR1
------------
NDREWA

SQL> /

STR1
------------
WERDNA

SQL>