Potion of Charisma?
 

Is Potion of Charisma exist or Ring or something..? if yes then what the price and what it do? (did it give you permanant +1 charm or not)

You can get the spell Charisma, which for a period of time will raise Charm (mine goes from 9 to 16) but it wears off after a few minutes. I have seen Rings of Charm, yes. Don't expect +1 Charm to make a huge difference, it will help a little but not as much as the Charisma spell.

EDIT: note that Charisma takes 12 sp (mana) to cast.