It looks like your private key seems to have been generated either in a different OS or SSH implementation which the SSH client does not understand. These lines are telling (more are included in the debug you gave):
debug3: Could not load "/home/oracle/.ssh/id_rsa" as a RSA1 public key
debug2: key_type_from_name: unknown key type '-----BEGIN'
debug3: key_read: missing keytype
debug3: key_read: missing whitespace
debug2: key_type_from_name: unknown key type '-----END'
debug3: key_read: missing keytype
Did you import it from a Linux or Windows machine? Perhaps you can try (re)generating a private key in the AIX client and upload that in the AIX server?
