The Aqidah of the Tamil Muslims is based on Sunnah basically influenced by the Sufis. Tamil Muslim families are patrilocal though their marriages incorporate Islamic mahr practice. For instance, it is common to see a groom pay the bride mahr sum of 10,000 rupees and the bride in turn would pay the groom a dowry sum of 100,000 rupees, though practice of dowry is banned by Islamic doctrines.
Tamil Muslims practice monogamy and male circumcision.
Like the thali of Tamil Hindu brides, Tamil Muslim women wear a chain strung with black beads called Karugamani which is tied by the groom's elder female relative to the bride's neck on the day of nikkah.
As a mark of modesty Tamil Muslim women usually wear white thuppatti (from Hindi/Urdu duppatta) instead of the black burqas (that are popular among Urdu-speaking Muslims) which is draped over their whole body on top of the saree. This has remained a hurdle in genealogical research.
Almost all Tamil Muslims go to Qabr (Dargah) ziyarat which is an important Sunnah.
The global purchasing power of Tamil Muslims in 2005 was estimated at almost $8 billion viz. $3 billion in Tamil Nadu, $1 billion in Malaysia, $600 million in Singapore.
Tamil Muslims have historically been money changers (not money lenders) throughout South Asia and South East Asia.
Generally Tamil Muslims are involved in various trades like retail, mutton shops, shops in foreign bazaar. They are also involved in gems trade & leather industry.
Due to the plenty opportunities in the Gulf region, a lot of Tamil Muslims went to the Gulf. Now Tamil Muslims are spread over in the Gulf countries and also in Singapore, Malaysia and Brunei.
The Tamil Muslim community is a prosperous one. There are about 400 millionaires within the community and at least one billionaire viz. B.S. Abdur Rahman (better known as the Buhari Group) who constructed the conglomerate ETA Star Group, Chennai Citi Centre, Chepauk Stadium, Marina Lighthouse, Valluvar Kottam, Government General Hospital, Gemini Flyover, Crescent Engineering College, et al.. He owns over 70 ocean-going vessels (ships).
Source: Tamil Muslim (Wikipedia)