Dear Willi ,
In this instantclient link with /oracle/client/11x_64/instantclient_11203,
as per below
xxxxx:xxxadm 44> cd client
sapxxx:xxxadm 45> ll
total 4
drwxrwxr-x 3 xxxadm sapsys 1024 May 30 2014 10x_64_OLD
drwxrwxrwx 3 xxxadm sapsys 1024 May 30 2014 11x_64
drwxr-xr-x 2 root root 96 Oct 23 21:39 lost+found
xxxxx:xxxadm 46> cd 11*
sapxxx:qasadm 47> ll
total 8
-rwxrwxrwx 1 xxxadm sapsys 163 Mar 14 2012 dbclient.lst
lrwxrwxrwx 1 xxxadm sapsys 41 May 30 2014 instantclient ->/oracle/client/11x_64/instantclient_11203
drwxrwxrwx 2 xxxadm sapsys 1024 May 29 2014 instantclient_11203
-rw-rw-rw- 1 xxxadm sapsys 1780 May 25 2014 trans.log
xxxxx:xxxadm 48> cd ../10x_64_OLD
xxxxx:xxxadm 49> ll
total 298
-rwxrwxr-x 1 xxxadm sapsys 112 May 18 2010 dbclient.lst
-rw-r--r-- 1 xxxadm sapsys 1084 May 21 2014 dev_sapstart
drwxrwx--- 2 xxxadm sapsys 1024 May 18 2010 instantclient_10204
-rw-rw-rw- 1 xxxadm sapsys 148171 May 25 2014 trans.log
xxxxxx:xxxadm 50>
Regards