Yes you can! There are always lots of open rendering jobs, especially with online retailing solutions nowadays at some point most companies will want to create either professional photographs, or with lower budgets, 3D renderings of their products created.
Your clients are very aware of the state-of-the-art and will demand the highest quality. You can start with simple product renderings and later step to jewelry, bottles, foods, vehicles etc. There is always a high demand, just know that you will not make as much as an artist compared to being an engineer, I would combine the two. A tip is not only to charge for your manhours but also a small fee for each hour rendered.
Post some of your work here if you want critiques.