What to do to increase hemoglobin level of body other than tablets and syrup?

Mate hemoglobin levels will increase naturally due to training adaptations. If you train aerobically your red blood cell count will increase in order to supply the required oxygen, subsequently your hemoglobin levels will spike as they are contained in blood cells. Otherwise you could spend some time at altitude for a few weeks which increases your oxygen carrying capacity, basically you have more hemoglobin to carry oxygen but this is only a short lived adaptation. Hope it helps?