Resolution:
Here are the steps  to run a Siebel Publisher as an NT Service.

- stop the Publisher NT service from Control Panel (If you have any)
- remove the publisher as NT service, by giving the following command:(if you have any)
        'tdservice -r pub'
- then give the following command to install publisher as NT service
       for remote repository
       ---------------------
                %TIB_SIEBEL_HOME%\bin\tdservice -i pub -p "%TIB_SIEBEL_HOME%\bin" -a
                "/system:repourl tibcr://dmo_si_test2_eai /system:configurl siebel/SafeContactPub"
                  (here, dmo_si_test2_eai is referred as remote repository)
        for local repo
      --------------
     %TIB_SIEBEL_HOME%\bin\tdservice -i pub -p "%TIB_SIEBEL_HOME%\bin" -a
                "/system:repourl c:\tibco\repository3.2.2\local\labsiebelDemo.dat /system:configurl siebel/SafeContactPub"
       (here, labsiebelDemo is referred as local repository)
      
- from Control Panel, start the service

- From NT Task Manager, you should get both 'tdservice' and 'tdpub' as processes.