joint family is more a cultural thing than religious thing
Yes, I agree. Some religiously family need this cultural thing, most of them mixed religions and culture things. Anyway, Italy is full of joint family system in their strong culture, i think.
bhai janab tabhi tu keh raha hun bhai k, burhape main pta chaly ga, in old age, a person is usually left alone, and nobody will be there to take care of you
Well, we know our old parents become old, they will always welcome to live with us to take care of them. It is common everyone.