The sixth day Prayers for Navratri is dedicated to Goddess Katyayani. Navratri Day 6 Mantra in Hindi is given below. It is chanted on October 19, 2015 during Navratri. There are three mantras. First is Mool Mantra for sixth day of Navratri. Second is Dhyan Shloka dedicated to Goddess Katyayani. Third is a Stotra. You can chant also prayers like Lalita Sahasranama on the day.
There is no need to chant all mantras. Most devotees chant just the mool mantra.