Info on visa status

I'm not entirety sure that this is the right place to ask this, but I'm going to try.

I'm an international student at the faculty of Economics, I've already done 2 years and I have 1 exam left.

Now that I have moved back to my country, my question is, do I have to extend my visa status in order to be a student at the faculty of Economics, or can I just travel occasionally to finish my studies and not have a student visa status?

I'm afraid that If i don't extend my visa I would loose my studies.