My mother had hysterectomy 5 months back , is it possible of bleeding and low haemoglobin level after surgery?

Many possibilities: While it is possible that the low haemoglobin is related to the hysterectomy, most patients recover to relatively normal levels within a few months of surgery. Late bleeding from a hysterectomy is fairly rare. You did not indicate the reason for the hysterectomy. If it was for non-cancer reasons, your mother's haemoglobin should have resolved by now. I would encourage her to have this evaluated.