What is the usual tradition around Indian wedding receptions in India?

My understanding is that it is a party arranged by the groom’s family, in the groom’s city, to celebrate the wedding and to introduce the bride to their family and friends. It is usually held 2 or 3 days after the wedding.

Few other people say its just another function which happens the same day of the wedding in the same venue where people can give gifts, etc , which in my thinking, is part of the wedding function itself, not a reception.

I know there are no strict rules but what is the usual procedure, specially in Gujarati weddings?