Hi Junior,
Prerequisites:
In the following special cases you need to obtain more information:
—If you are upgrading from Oracle 10.2 to Oracle Database 11g Release 2 (11.2) in manual mode (in this guide we only describe the database upgrade using the DBUA)
—If the source database runs Oracle 10.2 with patch set lower than 10.2.0.5, you need to first upgrade the source database to at least patch set 10.2.0.5.
Means - Exact Steps/Procedure mentioned in latest/updated upgrade guide is for database upgrades from 10.2.0.5 to 11gR2.
But same steps are applicable for database upgrades from 10.2.0.4 to 11gR2 also, Guide says to obtain more details before you proceed with upgrade.
Database upgrade from 10.2.0.4 to 11.2.0.2/higher is very well supported and the procedure is same as other upgrades (10.2.0.5 to 11gR2).
Regards,
Nick Loy