After foolowing all the suggested steps,
I got this

machine_name oracle Dbname /mountpoint/***/oracle/product/8.1.5/bin
$ file oracle
oracle: executable (RISC System/6000) or object module not stripped

machine_name oracle DBNAME /mountpoint/***/oracle/product/8.1.5/bin
$ $oracle_home/bin
ksh: /bin: 0403-006 Execute permission denied.

Can any body tell me why, I still could not find the bit?