$$\sum M_C = 0 $$
Thus,
$$(T_{AB} \cos(30^\circ) \cdot 2) + (T_{AB} \sin(30^\circ) \cdot 4) - (3 \cdot 2) - (4 \cdot 4) = 0$$$$T_{AB} = 0 \text{kN}$$$$\sum F_x = 0 $$
Thus,
$$C_x = T_{AB} \cos(30^\circ)$$$$C_x = 0 \text{kN}$$$$\sum F_y = 0 $$
Thus,
$$C_y + T_{AB} \sin(30^\circ) - 3 - 4 = 0$$$$C_y = 0 \text{kN}$$