Is it armulator integrated in the DS-5 suite ?
If so how to invoke the same and if not is it possible to integrate the same.
No. ARMulator (later called RVISS) was discontinued with RVDS. I do not know of any way of using it with DS-5.
DS-5 includes fixed virtual platforms, which give you a way of testing bare metal and Linux applications on your host machine. As Martin says, ARMulator was discontinued a while ago.