Southern Indian trade guilds were formed by merchants in order to organise and expand their trading activities. Trade guilds became channels through which Indian culture was exported to other lands, and these dominated trade in Southeast-Asia for several centuries, reaching their peak at the height of the Chola Empire's dominance, from the 11th century to the 13th century.
Several trade guilds operated in medieval Southern India, such as the Gatrigas, Nakaras, Mummuridandas, Ayyavole-500, Ubhayananadesigal, Settis, Settiguttas, Birudas, Biravaniges, Gavares, etc. Temples were the pivot around which socio-economic activities of the land revolved. Some trade guilds, such as the Nakaras and Gavares, met only in the temple premises, and some were powerful enough to decide the fortunes of kingdoms. One example of this is the Nanadesi trade guild, which not only financed local development projects and temple-constructions, but also lent money to the kings. The rulers did their best to accommodate the guilds because of the benefit they derived from them.
Trade guilds employed troops, enjoyed impunity, and had international connections and thus constituted a state within a state. Trade guilds were often independent bodies over which kings tried to exercise control; and sometimes failed. One such example relates to the bankers and money-changers of the Bahmani Kingdom, who ignored all warnings and melted all new coins that fell into their hands and supplied the metal to the mints of Warangal and Vijayanagar. Among the most notable of these merchant guilds were:
The Five Hundred Lords of Ayyavolu (Ayyovole-500): also known as Ayyavole, Ainnuruvar, Vira Balanju, vira banajigaru, vira balanjya, vira Valanjiyar, vira balija, Nanadesi, etc. They were a group of 500 Swamis who constituted themselves into a board of merchants in Aihole.
The Anjuvannam guild: consisting of Jewish, Christian and Muslim traders, this merchant guild operated in the ports of Malabar, Coromandal Coast and Java. This guild was defined by Y.Subbarayalu as a "body of west Asian traders". A Syrian Christian grant of 1220 AD bears signatures in Arabic, Hebrew and Pahlavi scripts, while a Tamil text refers to Muslim Anjuvannam traders in Nagapattinam. In a 1296 AD epigraphy of Tittandatanapuram, the Anjuvannam guild finds mention in a big assembly of several merchants and weavers including Manigramam and Valanjiyar of south Ilangai (Sri Lanka) indicating that it had an influential position in that settlement. The merchants of Anjuvannam guild of Manigarmam (of Kerala) were called Vanigar and were found along with the Nadu, Nagara, and various itinerant merchants (Samasta-Paradesi) of the 18-bhumi. They find mention in 1279 AD making some contribution to a local temple on the merchandise imported and exported at a local port (Nellore Inscriptions, I, Gudur 45).
The Nanadesi guild: were a group of various merchants. They find mention in the 14th century Tamil inscription recording the assurance of fair treatment by a local chief named Annapota Reddi. The Nanadesi guild and the Manigramam guild later joined the Ayyavole-500 guild.
The Sankarappadi and Saliya Nagarattar guilds: Two specialized merchant guilds which functioned in urban centres.
The Manigramam guild: flourished in Tamil Nadu in the Pallava and Chola periods, and was active in South-east Asia.
The Nakara guild: also known as Nagara and Nakaramu. This was a body of Vaishya devotees of Nakaresvara, headquartered in the town of Penugonda in the Godavari district of Andhra Pradesh. They were known as Nagara swamis or Nakarasvamulu; This word is found in Kannada inscriptions as Nakara and Nakhara, cf, as well as as Nagarathar, Nagarasvamin and Nagaravaru in other languages. This later became a local guild of the Ayyovale-500.
The Mummuridandas and Setti-Guttas: Last but not least, these were originally mercenary troops who protected the prabhumukhyalu (chiefs) of different Pekkandru (merchant) guilds. They were hired by traders to ensure protection of itinerant groups and caravans, and also to ensure the safety of trading settlements. They were warriors first and merchants second, and had branched off from the Ayyavole-500.
These merchant guilds traded in a wide variety of goods- areca nuts, betel leaves, any number of fruits and vegetables, tumeric, onions, ginger, grains, pulses, oils, spices, indigo and other dyes, paints, silk, wool, cotton, camphor, civet, musk, sandalwood and other cosmetic products, ivory, coral, pearls, rudraksha (prayer bead seeds, most associated with Shaivism- produced by species in the genus Elaeocarpus, and many of the largest and most colorful of these happen to be produced by Elaecarpus species native to Australia), precious and semi-precious stones, and any number of other products. So then, how plausible would it be, in your opinion, for a few of these South Indian merchant guilds' more enterprising branch leaders to set about establishing colonial trade settlements on Australia? And how successful could they plausibly have been in colonizing Australia? How different could you envision TTL's Australia being from IOTL's Australia, by the time the first Europeans arrived in the region?