if i am a commerce student should i do a minor in econ? will it have any use to perspective employers

Yes a minor in econ is great to have and put on a resume (because i have done that) but employers are looking for experience, extra-curricular, and grades, the minor in econ is more of a personal achievement

anything to set yourself apart from the competition is good, but you should have an interest in economics before pursuing a minor. If you happen to like econ than doing a minor is a great idea.

I think being in commerce and having a minor in econ is a little pointless. That would be like (chem bio) having a minor in biochem.
But if you were to say minor in something that's very very different than your major (like math), then that would make you stand out even more.