Your Gross revenue is over $1,000 but the Income is not (based on your post). If you look at page 5 of 511-NR, it says that the Oklahoma income includes "Net Rent." That is after expenses and depreciation. You definitely do not have to file.
However you may still be allowed to file. If you look at that link on page 5, you will see that the loss year must be filed to establish the Oklahoma Net Operating Loss.
