Code:
I have Installed 2 DBs on our AIX 5L server, 9i and 10g db with HOMES at
/u01/app/oracle/prodcut/9.2.0.1 and
/u01/app/oracle/product/10.1.0.2 respectively.
Lately i deinstalled 9i to recover some disk spaces and remove its
corresponding file system directory.

My problem is i can not start my listener for 10g db...i got error 
TNS-01201: Listener cannot find executable /u01/oracle/product/9.2.0.1/bin/oracle for SID ora9i
Listener failed to start
You still have files in 9i Oracle home not completely removed.
Check the path as the listener is looking for the 9i executable.

set the 10g SID and see if the services are started to start the 10g listener.