Given circle x2+y2−2gx+6y−19c=0
Also given circle passes through (6,1)
So, 12g+19c=43⋯(1)
And centre (g,−3) lies on x−2cy=8,
So, g+6c=8…(2)
On solving equation (1) and (2) we get, c=1 and g=2
Now equation of circle will be, x2+y2−4x+6y−19=0
Now length of intercept on x-axis is given by =2g2−C=222+19=223