Answer:
Vmax = 192.33 cm³
Step-by-step explanation: An error in the problem statement. The sides of the box could not be 12 cm. We assume 1.5 cm
Inside dimensions of the box:
Outer dimensions : Â Â Â Â Â 12 Â Â Â Â Â 10 Â Â Â Â 8
 2 *  1.5  =  3            3       3     3
Inside dimensions: Â Â Â Â Â Â 9 Â Â Â Â Â Â 7 Â Â Â Â 5
The volume of a right circular cylinder is:
V(c)  =  π*r²*h        r is the radius of the base and  h the height
By simple inspection is obvious that volume maximum will occur when r is maximum, and r is maximum, only when the base of the cylinder is in the rectangle 12*10. ( Inside  dim  9*7 ) In that case r  =  7/2  r = 3.5 cm
Then the height is 5 cm.
And the maximum volume of the cylinder is:
Vmax = 3.14* ( 3.5)²*5
Vmax = 192.33 cm³