It is performed when a family moves into a new house or apartment and is considered an auspicious occasion. Here are some of the housewarming rituals that are commonly practiced in India:

1. Preparing the House: Before the ceremony, the house is thoroughly cleaned and decorated with flowers, rangoli, and other traditional items. This is done to create a positive and welcoming atmosphere.
2. Ganesh Puja: The ceremony usually begins with a Ganesh Puja, which is performed to remove any obstacles and to seek the blessings of Lord Ganesha.
3. Lighting the Lamp: A lamp is lit to symbolize the presence of the divine and to bring positivity and prosperity into the new home.
4. Kalash Puja: A Kalash (a copper pot filled with water and mango leaves) is placed at the entrance of the house, and a puja is performed to invoke the blessings of the gods.
5. Vastu Puja: Vastu Puja is performed to ensure that the new house is constructed in accordance with Vastu Shastra, an ancient Hindu science of architecture.
6. Havan: A Havan is a fire ritual that is performed to purify the new home and to offer prayers to the gods.
7. Griha Pravesh: The main ritual of the housewarming ceremony is the Griha Pravesh, which is performed when the family enters the new house for the first time. The head of the family carries a small fire pot and walks around the house, while the priest recites mantras to bless the house and its inhabitants.
8. Food Offering: The ceremony ends with a feast, where the family and guests are served a variety of traditional dishes. It is believed that offering food to the gods and sharing it with others brings good fortune and happiness.