Can we use Having as possession
1) i am having a car
2) i am having 2 brother
In most varieties of English have can take the continuous form only when it has a meaning other than possess. Examples:
We're having a party next week. (having = organising, arranging, holding)
I'm having some difficulties. (having = experiencing; Present continuous)
I would say "I'm having a car" only in the sense of "I have arranged to hire or borrow a car", and I can't think of any contexts in which I would say "I am having a brother".
However, my impression is that Indian English uses continuous forms more than other varieties, and that sentences like yours are common in Indian English.