Although there are some tea plantations and factories in certain lower and central districts of Assam, five upper districts -- Tinsukia, Dibrugarh, Sivsagar, Jorhat and Golaghat -- are the prominent tea producing areas.
At least 45 percent of the state's tea factories are in these districts and produce not less than a million kilograms of tea every day.
The move is expected to boost small tea growers in Assam, who together contribute at least 30 percent of the state's total tea production, Saini said.
A majority of the small tea plantations in Assam are also located in these five districts.
The Jorhat district in upper Assam also houses the Tocklai Experimental Station (TES).
Established in 1911, TES is also the oldest and the largest research station of its kind in the world where research on all aspects of tea cultivation and processing is carried out.
The new board office in Jorhat is likely to start functioning from next month.
Saini said the board has also decided to open a separate directorate in Dibrugarh for small tea growers.
The directorate is likely to become operational from October, he said.
Assam's Brahmaputra Valley is the world's single-largest tea producing area.
Apart from numerous small tea growers, Assam has about 850 large tea gardens and the state produces about 51 percent of India's total tea.