Thnx everyone
I was finally able to do something about the problem
Here is what i did for anyone who faces the same problem
I downloaded the Kotor Save Game Editor from http://www.pcgamemods.com/7392 and theen used it to change Vrook's status to 1 from 2 and was able to free him
now back to gaming
Sadly , No .... I though i would get some key or something like that to relase him rom his force cage and hence i have progressed far ahead in the game
At Dantooine i have defeated the mercs tht captured Vrook but i am still unable to free him from his cage.I have already serch every corner of dantooine without ny success...plz tell wht to do