Session Create Runtime DD for tools was killed accidently. Because of this I am not able to run any tools session. Even GTM /GTD is not working.
What must be the problem ? Is reinstallation is only alternative ?

If you have a backup, restore the $BSE/tools/dd directory and the table ttadv999000. Did you try all package combinations, that are on your system? Maybe the entries for the tools of one pc is still ok.