yes, product
$i=1$, So elements are $a_{1}$
$i=2$, So elements are $\left \{ a_{1},a_{2} \right \}$
$i=3$, So elements are $\left \{ a_{1},a_{2},a_{3} \right \}$
.......................................
Now, $G=\left \{ a_{1},a_{2},a_{3},............,a_{12} \right \}$, here order of group is $12$, So order of it's subgroup
$1,2,3,6,12$
Now if we do product of these elements , it will be $a_{1}.$$\left \{ a_{1},a_{2} \right \}$$.\left \{ a_{1},a_{2},a_{3} \right \}........$$\left \{ a_{1},a_{2},a_{3},............,a_{12} \right \}$
So, order will be $1,2,3,6,12$
right??