Okay so I'm a fourth year student at NLUD and honestly wouldn't have cared enough to reply to this post until I saw WRONG information being given to you by your immediate seniors (kids these days).
There ARE a handful of students who do not stay on campus at all. Both boys and girls - not a lot of them, but like I said a handful, due to exceptional circumstances of course. So you can just speak to your warden about it and explain your situation to them and they will allow it. And as per the procedure for doing so, I'm not sure, so it would be best if you speak to your warden on the orientation day and they'll help you out with it.
And once it is allowed and you are sure that you dont want to stay in the hostel AT ALL, you need not even pay the hostel fees. Of course that can be worked out later. But yeah, it IS allowed.
And to all juniors, PLEASE get your facts straight before HELPING out freshers. It's okay if you don't give them any information, but at least don't give them wrong information.