Assuming the object is a cuboid with the given dimensions and it’s the surface area you’re talking about, there are 6 faces, 3 pairs of the same area—two sides with area 2×6=12cm², two sides with area 2×5=10cm², and top and bottom each with area 5×6=30cm², making a total of 2(12+10+30)=2×52=104cm².
(The volume is 2×5×6=60cm³.)