Importing 11gR2 dump into 10gR2 Database

1. The expdp command with version parameter can be used as follows on the source database (11g).
  #expdp user/pwd file=11g1.dmp version='10.2.0.1' dumpfile=my10gv.dmp directory=dump_dir

2. Import dum file to target database (10g).
  #impdp user/pwd dumpfile=my10gv.dmp