Hi Gaurav,
As far as I understood the question, your query is the task that is being run in one client should not be available on the other client machine right if that's the case following will be the answer:
If you upload any task to control room then only we can use that task on the other machine using AA. If two clients wants to run same task directly on the control room then it'll not be possible the one who runs it will have the control the next person has to wait until task becomes free or download the task from control room to client machine and the run individually
For version controlled tasks PFA this is obtained from control room user manual page 20
Hope this might have helped you...