I cant tell you if its safe or not, but I can tell you one thing:
BSNL assigns ports to each user (it has a technical term, forgot) that means even if your username and password is known to another person, he can use it only from your telephone line, and not anywhere else. So, unless you are worried about someone in your house knowing the user/pass, go ahead
PS: I dont know anything about this quick finder tool, just providing my piece of info.