Given equation of circle is
$x^{2}+y^{2}+3 x+2 y-8=0$
On comparing with
$x^{2}+y^{2}+2 g \,x+2 f\, y+c=0,$ we get
$g=\frac{3}{2}, \,\,\,\,f=1$ and $ c=-8$
Now, intercept made by $y$ -axis
$=2 \sqrt{f^{2}-c} $
$=2 \sqrt{(1)^{2}-(-8)} $
$=2 \sqrt{1+8}=2 \sqrt{9} $
$=2 \times 3=6$