Solution : https://service.sap.com/sap/support/notes/98252 (SAP Service marketplace login required)
Key words : 
/oracle/c12/<oracle_version>_<bit>/network/admin/tnsnames, /oracle/c11/<oracle_version>_<bit>/network/admin/tnsnames, /oracle/c12/<oracle_version>_<bit>/network/admin/listener, /oracle/c11/<oracle_version>_<bit>/network/admin/listener, /oracle/c11/920_64/network/admin/listener, /oracle/c12/network/admin/tnsnames, /oracle/c11/network/admin/tnsnames, /oracle/c12/network/admin/listener, /oracle/c11/network/admin/listener, named sap web application server
Related Notes : 
       
| 562403 | FAQ: Oracle Net | 
| 158709 | Installation SAP R/3 64 bit kernel ReliantUNIX | 
| 101318 | INST: 4.0B R/3 Inst. on UNIX - Oracle Database | 
| 21960 | Several instances/systems on one UNIX computer |