6. Determine the equation of the spherical surface $S$, with centre on the line $r: \left\{ \begin{array}{l} x = t \\ y = t \\ z = t \end{array} \right. t \in \mathbb{R}$ tangent to the plane $\pi: 3x - y - 2z + 14 = 0$ at the point $T(-4, 0, 1)$.
6. Determine the equation of the spherical surface $S$, with centre on the line $r: \left\{ \begin{array}{l} x = t \\ y = t \\ z = t \end{array} \right. t \in \mathbb{R}$ tangent to the plane $\pi: 3x - y - 2z + 14 = 0$ at the point $T(-4, 0, 1)$.