For low fat, it depends on what dishes you're ordering. Dishes like Laksa that has coconut milk in its broth is probably not low fat. Go to their web site and see what dishes could potentially be low fat. I don't believe they state which is low fat but I may be wrong.
As for low salt, that's something that you can possibly mention to the staff when you place your order. I know that they are fine to make slight adjustments if there are ingredients in your dish that you're not keen on.