I have struggled with this problem often.

The primary problem is that the setver.exe that came with
your distribution of DOS 6.0 is not lying properly to the
rdrload.exe program. There are
several versions of setver.exe, some work, some don't.

Try the setver.exe that comes with DOS 6.2.

The following brute force method has always worked when
other methods fail, even with a bad setver.

You can load starlan from a bat file after you switch
to the DOS 5.0 redir.exe.
Here is an example which assumes that the computer name is
compname, the servername is server, and the StarLAN 3.2 files
are in the attnet directory on the dos pc.

This bat file can also be used to set portions of
the network software into high memory.

attstart.bat

@echo off
cd c:\attnet
c:\attnet\attcfg
c:\attnet\iso
c:\attnet\vertbl
rem parameters for redir from profile.sys
c:\attnet\redir /b:2 /z:4096 /s:10 /l:12 /p1:256 /p2:128 /p3:128
c:\attnet\setname compname
c:\attnet\prtsc
c:\attnet\nps
c:\attnet\msgpop
ql link n: \\server.serve\attutil
call n:\netstart 
call netstart.bat compname z: server.serve
exit