The Indian Commission Agents ( Banyans/Dubashis) - Colonial British India

East India Company flag (1801)en.wikipedia.org
The term ''Banyan'' (from caste term Baneah) implies a Hindu merchant, shopkeeper or confidential cashier and broker. The term was used in Bengal to designate the native who managed the money concerns of the European, and sometimes served him as an interpreter. In plain term, he was a 'commission agent' for the Europeans who arrived in India to engage in mercantile trade and business and acted as an intermediary between Europeans and Indian goods manufacturers or business people. These so called agents were closely associated with the British East India Company that landed in India in the 1700s to engage in mercantile trade in cotton, Indigo, spices, silk, etc. They got trading concessions from the then  Mogul ruler  after 1634. Their trading activities began to  spread across slowly and they established the Madras Residency and Calcutta residency with forts and factories to carry on their trading activities.  With the expansion of their business they needed the help of people who were bilingual -knowing English and the local language spoken  in that region.
 Banyan (agent)-a native of Surat.Brtish India. diwancybermuseum.com
At Madras (now Chennai, Tamil Nadu) the person of same description was called a Dubashi (meanig bilingual), one who could speak, besides English, two local languages - Tamil or Telugu. Subsequently these Dubashis at Madras became influential and well-known merchants. They were very close to their British sahibs and wielded enormous powers. It was inconceivable what property was in their hands. They were  ostensible agents in every line of business, placing their dependents in the several departments over which they themselves had obtained dominion. If a contract was to be made with the Government by any gentlemen not in the Company's service, the banyans became the securities, under the condition of receiving a percentage. When a person in the service of the Company was an indirect beneficiary which he was unable to enjoy for some reason, then the banyan became the principal agent , and the donor either received a share or derived advantage from loans. The same person frequently was banyan/intermediary to several European gentlemen, all of whose concerns were, of course, accurately known to him, and thus became the subject of conversation.

Possessing large properties  with most extensive credit and influence they were absolute monarchs in their respective fields of operations. So vast was their influence that Calcutta was once under the control of about 20 or 30 banyans, who managed every concern in which they could lay their hands on and find means to make a profit. Likewise Madras had about 12 Dubashis, acting as intermediaries between the natives and British Sahibs (Durai). They very well knew the horoscope of English sahibs and their planet positions!! They knew their weakness as well as strength.
It was impossible for British men to carry on his daily activities, particularly trading without support from Banyans. Obviously these people enjoyed political clout, pelf and power. At one point of time corrupt British officials in the Madras Residency engaged in financial irregularities and the Indian agents were their accomplices.  No body, not even the rulers could see the governor without obliging the chief Dubashi. (source: from a few  references that made a mention of colonial agents)