The primary agency for agricultural marketing and regulation in Tamil Nadu is:

Tamil Nadu State Agricultural Marketing Board
NAFED
APMC
FCI

The primary agency for agricultural marketing and regulation in Tamil Nadu is the Tamil Nadu State Agricultural Marketing Board (TNASMB). The TNASMB was established in 1965 to promote the development of agricultural marketing in the state. It is responsible for regulating the marketing of agricultural produce, providing marketing infrastructure, and promoting the interests of farmers.

The TNASMB has a network of over 1,000 markets across the state. These markets provide a platform for farmers to sell their produce to buyers. The TNASMB also provides marketing infrastructure such as warehouses, cold storage facilities, and grading and packing facilities.

The TNASMB also promotes the interests of farmers by providing them with information on market prices, by helping them to form cooperatives, and by providing them with financial assistance.

NAFED is the National Agricultural Cooperative Marketing Federation of India. It is a cooperative society that was established in 1958. NAFED is responsible for the procurement, storage, processing, and marketing of agricultural produce. It also provides marketing infrastructure to farmers and promotes the interests of farmers.

APMC is the Agricultural Produce Market Committee. It is a statutory body that is responsible for regulating the marketing of agricultural produce in a particular area. APMCs are responsible for setting up and maintaining markets, for regulating the prices of agricultural produce, and for providing marketing infrastructure to farmers.

FCI is the Food Corporation of India. It is a government-owned corporation that is responsible for the procurement, storage, and distribution of food grains. FCI also provides marketing infrastructure to farmers and promotes the interests of farmers.

In conclusion, the primary agency for agricultural marketing and regulation in Tamil Nadu is the Tamil Nadu State Agricultural Marketing Board (TNASMB). The TNASMB was established in 1965 to promote the development of agricultural marketing in the state. It is responsible for regulating the marketing of agricultural produce, providing marketing infrastructure, and promoting the interests of farmers.