Hello student. An average student can definitely do cs along with bcom.  I cannot exactly put it as easy, but it is possible with efforts and more over it will be useful too.

It will help you to learn alot more. Most of the subjects in bcom will be covered by CS. To prepare for bcom exams too, you can use CS study material and manuals etc.

But the thing it, it is highly difficult if you rely on only class room learning. You should be able to plan and prepare for self study. For self learning. Plan your time properly and you will definitely be able to do it

All the best

Regards

Nikhitha