If you sublet a unit for 8 months and there is not net income does it need to be reported. I assume it cannot be claimed as an expense then for those 8 months.?

If you intention was to make a profit, and you are renting the space at fair market rates, then yes, you can claim your expenses. However, you can only claim expenses for the time your property was rented out, or you were actively searching for someone to rent it.