Karta means manager of joint family and joint family properties. He is the person who takes care of day to day expenses of the family looks after the family and protects the joint family properties. It is a presumption that ordinarily senior most male member is the Karta and Karta is always a member in the family no outsider or stranger can become a Karta.
The senior most male member so long as he is alive may be, aged, infirm or ailing continues as Karta. By his death Kartaship will pass on to next senior most male member. In the presence of senior most male member a junior cannot act as Karta but if all coparcener agree, a junior also can become a Karta. Karta owes his position by consent or agreement of all coparceners.