SQL & PL/SQL :: Convert Datetime To Date?

I know this question has been asked several times. but i am starting out and i am struggling to get my head aroung it.I would like to convert datetime column of Oracle source(RPT.SHIPMENT_VW) to date while loading to sql Here is my

SELECT SHIPMENT_NBR,RECEIVED_DATE_TIME, RCVD_AT_DATE_GMT_FK
FROM RPT.SHIPMENT_VW
where WHERE RECEIVED_DATE_TIME = TO_DATE(TO_CHAR(:fromdate, 'DD/MM/YYYY'))
here RECEIVED_DATE_TIME is in 'DD/MM/YY hh:mi:si' fromat which, i want to convert to 'DD/MM/YY'
the above code throwing an error ORA:01843 not a valid month

if I use where clause like:WHERE (RECEIVED_DATE_TIME = TO_DATE(TO_CHAR(:fromdate, 'DD/MM/YYYY'), 'DD/MM/YY'))then its not retrieving any data