Whenever i take antibiotics, dryfruitsand supari..then mouth ulcers hits all over in my mouth including tongue...why..?

Sensitivity: Sounds like you have a sensitivity to these items. I would suggest to refrain from using that specific antibiotic and food item.

Abx immune system: Antibiotics can affect one's immune system in many ways. Mouth ulcers can be a reaction to an altered immune system. Sometimes an antibiotic will lead to a fungal infection in the mouth. Check with your md if this persists. Also, though very rare: ask your md to be sure there are not other signs of behcets syndrome or other immune conditions if you continue to have unexplained mouth ulcers.