By a Staff Reporter: Rakhi Purnima is very sacred in Hinduism. On this day, their sisters wish the brothers well. By tying rakhis on the hands of the brothers, the sisters drive away the evil. But even though we all celebrate Rakhi, many of us do not know which Tithi Rakhi is for Rakhi Purnima. Rakhi Purnima is celebrate on the full moon Tithi of the month of Shravan (Bengali Mounth).