You can use
impdp utility by Oracle for migration of database from 11g to 12c.
First of all we will use expdp utility to export the whole database into a dumpfile (.dmp) by issuing the following command:
expdp system/password@db11g full=Y directory=TEST_DIR dumpfile=DB11G.dmp logfile=expdpDB11G.log
Here, FULL parameter indicates that the whole database will be exported
Directory --> The directory on server in which you want to place the dumpfile
DUMPFILE --> The name of dumpfile
LOGFILE --> The name of logfile (that logs the status of export process)
After the export is done successfully you will get something like:
Job "SYSTEM"."SYS_EXPORT_FULL_01" successfully completed at 10:35
Now, your whole database is stored in a dumfile(.dmp) in the 'DIRECTORY' mentioned in the expdp command.
We will now start import of the database into 12c database with the help of impdp utility.
impdp system/password@db10g full=Y directory=TEST_DIR dumpfile=DB11G.dmp logfile=impdpDB12c.log
*Before starting import you might need to transfer the dumpfile to the new server (i.e. 12c)
After import has been successfully completed you will get successfull completion message.
Reference link --> https://oracle-base.com/articles/10g/oracle-data-pump-10g
Happy Migration !!