Chaitra Navratri Parana is performing on the Dashami Tithi of Chaitra Shukla Paksha (bright fortnight of the Hindu month, Chaitra). It is the day when Nine-day Chaitra Navratri fair comes to an end.
Though there are contradictory statements in the Shastras to make a decision if the Parana must be perform on the Navami or Dashami, yet Mimansas (those who have describe the Shastras) suggest performing it on Dashami. They agreed on Dashami Tithi because one can find many texts that hint keep fast on Navami.
If Navami Tithi is happening on 2nd day, fast must be kept on the 1st day and Parana must be performed on the 2nd day of Navami. (It is suggested by the Shastras.)
As it is the last day of Navratri Pooja, Bhagwati Durga Visarjan must be performing after Shodhashopchar Pooja.
After Pooja and Visarjan, offer food, gifts, etc. (as per your wish) to the Brahmins. Also, offer these things to the 9 little girls and perform Kanya Poojan.
We, at Dia199.com wish you a very happy Navratri!