Grihapravesham or griha pravesh pooja is the entry of the new bride into her in-law's place. Usually, weddings in India, especially in South India are conducted in a marriage hall. A marriage hall is designed in such a way that there are specific rooms for the bride's family and the groom's family. If the groom stays in the same town/city where the wedding is conducted then the newly wedded bride is taken to the in-law's house by her parents.

Significance of Grihapravesham Ritual in Tamil Brahmin Iyengar Weddings
Welcoming the Bride-When the Groom is from the Same Place
As per this traditional Tamil Iyengar wedding ceremony, the bride is welcomed into the in-law's house with an Aarthi and is offered flowers and sweets. The maatuponnu (a name that Tamil Brahmins call their daughter-in-law which signifies that she is also a daughter) is then made to sit on a low wooden plank called the Manai, and her in-laws give her milk to drink. She is gifted a new saree which she has to wear and light the sacred lamp in the puja room called the ‘Kuthu vilakku’.

Welcoming the Bride-When the Groom is from a Different Geography
In case the groom and his family hail from a different town than the place where the wedding happens, the Grihapravesham is performed when the bride enters the groom's room (The groom’s room in the kalyana mandapam is considered as his temporary residence as it would be difficult for the newlyweds to travel to the actual residence of the groom). Once the post-wedding rituals are complete and the newlyweds reach their home, they perform the Grihapravesham ritual again offering Aarthi and sweets. The bride also lights the 'Kuthu Vilakku' and becomes a part of the bridegroom's family. 

Checklist of things that need to be kept ready in a groom’s house for Grihapravesham:

• For Arathi: Aarathi plate along with little water, sunnambu, few Vethalai, karpooram and matchbox
• Manai(plank) and milk
• New Saree to be gifted to the Bride
• Kuthu vilakku with lamp oil, thiri and a matchbox