The equations of sides $AB$ and $AC$ of a triangle $ABC$ are $( \lambda + 1 ) x + \lambda y = 4$ and $\lambda x + ( 1 - \lambda ) y + \lambda = 0$ respectively. Its vertex $A$ is on the $y$-axis and its orthocentre is $( 1,2 )$. The length of the tangent from the point $C$ to the part of the parabola $y ^ { 2 } = 6 x$ in the first quadrant is\\
(1) $\sqrt { 6 }$\\
(2) $2 \sqrt { 2 }$\\
(3) 2\\
(4) 4