Positioning the brackets is the most important step in fitting braces. Not every bracket should be bonded in the centre of the tooth. Each type of brace has a position on the tooth recommended by the manufacturer, so that the bracket can carry out the movement it's designed for as fully as possible. Different bites can also call for differences in positioning – for example, with a deep bite the front brackets may be bonded closer to the biting edges of the incisors, whereas with an open bite it's the other way round – they sit closer to the gum on the same teeth.
This answer is for general information. Your own case needs an examination by an orthodontist.