For filling a complaint to police department, there is no procedure involved. You have to approach the police and write down the entire incidents from the date of marriage or from the date of the incident when the dowry was first asked for. the list of articles given in marriage for dowry needs to be attached along with the complaint. further, all the incidents needs to be mentioned specfically in the complaint. A complaint for 498A needs to be elaborate and specific giving a narration of all the cruelty meted out to the complainant.