Sourav,
Sounds like there is another possible match for 200 such as a DN, route pattern, or translation pattern that begins with 200. Callmanager is waiting for additional digits to find the best match. If possible, change the DN or other match to be unique. If not, you can tune down the T302 timer in CCM under Service -> Service Parameters -> Cisco Callmanager Service -> T302 Timer.
Hope this helps. If so, please rate the post.
Brandon