I$1$: add $s$0,$$t$0,$$t$1$

I$2$: sub $t$2,$$s$0,$$t$3$

I$3$: add $t$0,$$so$,$$t$2$

I$4$: lw $s$1,200($$$0)$

I$5$: add $t$1,$$t$2,$$s$1$

I$6$: sub $s$2,$$t$3,$$s$3$

you can perform the following Re$-$Ordering steps

$*$

move I$5$ after I$3$

move I$5$ before I$2$

move I$3$ before I$4$

move I$6$ before or after all other instructions