1. Clear the net services topology data model ..

To deregister the current application tier from the Net Services Topology Data Model, invoke the following command :

perl <AD_TOP>/bin/adgentns.pl appspass=<APPSpwd> contextfile=<CONTEXT> -removeserver

To deregister the current database tier from the Net Services Topology Data Model, invoke the following command :

perl <RDBMS ORACLE_HOME>/appsutil/bin/adgentns.pl appspass=< APPSpwd> contextfile=<CONTEXT> - removeserver

2. Clear the FND_NODES table as described in Note 260887.1 - 'Steps to Clean Nonexistent Nodes or IP Addresses from FND_NODES'

Execute following commands in SQLPlus :

EXEC FND_CONC_CLONE.SETUP_CLEAN;
COMMIT;
EXIT;

3. Run AutoConfig on all nodes - first on the DB-Tier and then on the APPS-Tier-node(s), to repopulate the required system tables.