Assembly elections in the two states are likely to be held early next year. Tripura is particularly high on the saffron party's agenda where it is working overtime to dethrone the Left Front government.
Party chief Amit Shah made the appointments, a statement said.
The BJP has long been a marginal force in these two states but made rapid strides in the entire region since it came to power at the Centre in 2014 and Shah took over its leadership. It is now in power in some northeastern states.