There's no rule for chanting this mantra but it's used at diverse locations According to the situation. For anyone who is utilizing it then utilize it in the manner given underneath.  ॥ ॐ नमो भगवते रुक्मिणीवल्लभाये स्वाहा ॥ This could assist to influence the magic much more. So, such a mantra https://www.youtube.com/watch?v=WG3Cevb_VHM