String to timestamp in datastage 9.1.2
You can use TO_TIMESTAMP_TZ Function:

SELECT 
   TO_TIMESTAMP_TZ('150601172623+0530', 'RRMMDDHH24MISS+TZHTZM'), 
   TO_TIMESTAMP_TZ('150601172041+0530', 'RRMMDDHH24MISS+TZHTZM') 
FROM dual;


2015-06-01 17:26:23.000000000 +05:30   2015-06-01 17:20:41.000000000 +05:30