I got elevated erithrocytes level in macroscopic urine test (50/ul) but negative results for protein, bacteria, etc. Is that considered okay?

Abnormal. Erythrocytes, or red blood cells, should not be present in your urine. Something is causing bleeding but this could be anything from a clotting defect, infection, tumor, tuberculosis, and so on. You need to be seen by a urologist and thoroughly evaluated.