As per your suggestion i created export file in 11g(220.127.116.11) using expdp and version parameter. On the target database which is on 10g(10.2.0.4) i dropped the schema, recreated schema and given all the appropriate grants. While importing using below command....
c:> impdp tril/tril@dbname schemas=tril directory=test_dir dumpfile=filename.dmp logfile=abc.log
got the error...
error " ORA-31684: Object type USER:"TRIL" already exists "
As per my understanding this error should not come because before importing we have recreated schema. Rest everything is imported perfectly..(objects like tables,procedures,functions,packages)..