There is an answer for this problem at http://www.puschitz.com/InstallingOracle9i.html
* /runInstaller: line 58: ./runInstaller: cannot execute binary file.
You are probably trying to run a 64-bit Oracle version on a 32-bit Linux system. Make sure you downloaded the right Oracle version for your Linux system.
To check if runInstaller is a 32-bit binary or a 64-bit binary, run the following command:
$ cd /mnt/cdrom
$ file install/linux/runInstaller
install/linux/runInstaller: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.0.0, dynamically linked (uses shared libs), not stripped
To check if your Linux system is 32-bit system or a 64-bit system, run e.g. the following command:
$ file /sbin/init
/sbin/init: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), not stripped