Quick Answer: Indian wedding rituals vary dramatically by region, religion, and community. Punjabi Sikh weddings feature the Anand Karaj ceremony — meaning "Act towards happiness" — where the couple makes 4 circumambulations (lavan) around the Guru Granth Sahib, the Sikh holy scripture, with no fire ceremony and no priest (the ceremony is conducted by a granthi). Bengali Hindu weddings center on the sindoor daan (groom applies vermilion to bride's hair) and the bride's shankha-pola (white and red bangles). Tamil Brahmin weddings feature the Kashi Yatra (groom pretends to leave for pilgrimage) and the Oonjal (swing ceremony). Marwari weddings are elaborate multi-day affairs with mehendi, haldi, and phere (7 circumambulations of the sacred fire). According to Wikipedia, the Sikh Anand Karaj ceremony has been recognized by the Indian Government since 1909.
Sikh weddings follow the Anand Karaj, introduced by the third Sikh Guru, Guru Amar Das, and legally recognized since 1909. The ceremony features 4 Lavan (circumambulations) around the Guru Granth Sahib while four hymns composed by Guru Ram Das are sung. Unlike Hindu weddings, there is no fire ceremony — the Guru Granth Sahib is the witness. Sikhism emphasizes equality, so the ceremony treats the couple as equal partners with no kanyadaan. The ceremony takes place in a Gurdwara with guests seated on the floor covering their heads.
Bengali weddings feature sindoor daan (groom applies vermilion to bride's hair parting), shankha-pola (white conch shell bangles on left wrist, red coral bangles on right), loha (iron bangle for protection), subho drishti (couple sees each other for the first time as married), and a sacred fire ceremony. Bengali brides wear red and white Banarasi silk sarees with a shola (pith crown). Tamil Brahmin weddings span 3-5 days with Kashi Yatra (groom pretends to leave for Varanasi), Oonjal (swing ceremony), Muhurtham (groom ties thaali gold pendant on yellow thread), and Saptapadi (7 steps). Marwari weddings are 3-7 day elaborate affairs with mehendi, haldi, sangeet, phere (7 fire circumambulations), vidaai, and griha pravesh.