There are very specific steps when upgrading an Oracle Applications database. In your case, you will want to refer to the Metalink Doc ID: 216550.1 (Oracle Applications Release 11i with Oracle9i Release 2).
Also, note that only Oracle Applications Release 11.5.7 or later is certified for use with Oracle9i Release 2 (9.2.0). Check the certification matrix on Metalink or OTN to make sure that your platform and environment configuration are certified to work with Oracle9i before performing an upgrade.
This was first published in February 2006