The following query:
select cdate from rprt where cdate <= TO_CHAR(sysdate, \'YYYY/MM/DD-HH24-MI-SS-SSSSS\') and ryg=\'R\' and cnum=\'C002\';
If you want the value from your timestamp column to come back as a date datatype, use something like this:
select trunc(my_timestamp_column,'dd') as my_date_column from my_table;