I used all commands as in omnetpp installation guide (https://doc.omnetpp.org/omnetpp/InstallGuide.pdf) and also according to this answer. The $ make command worked and I also verified installation with:
$ cd samples/aloha
$ ./aloha
which started using qtenv.
but the problem is that the $ omnetpp command doest work with after printing
Starting the OMNeT++ IDE...
and eclipse IDE does not open. is it possible to use this IDE in m1 Macs? is there any alternate IDEs to workaround?
You did not specify what version of OMNeT++ you were trying to run. I'm assuming 5.6.
OMNeT++ 5.6 relies on the system-wide installed JRE to run the IDE. That may NOT be present on your system if you are running on ARM. OMNeT++ 6 and 5.7 comes with a built-in private JRE, so the IDE should work with those versions also in intel emulation mode.