Solution : https://service.sap.com/sap/support/notes/858869 (SAP Service marketplace login required)
Key words : 
ja16sjis          japaneseko16ksc5601       koreanzhs16cgb231280    simplified chinesezht16big5         traditional chineseif, oracle version 9i mentioned, install sap kernel version 7, oracle client library version 9, oracle 10g client library, oracle client library, changed oracle implementation, extended maintenance contract, multibyte character set, kernel versions 31i_ext
Related Notes : 
       
| 1319517 | Unicode Collection Note | 
| 886784 | Updating to Kernel 640 when using multibyte charactersets. | 
| 695899 | Multibyte character set in SAP-R/3 | 
| 644939 | Maintenance extension for Oracle Version 8.1.7 | 
| 606359 | FAQ: Oracle National Language Support (NLS) |