Aunty is a common conversation word in India. Be it Hindi or English, you can hear this derivative of 'aunt' easily, when the context is relatives or neighbors. Basically Aunty in India is a word u can use for any lady of middle age, be it a distant relative, or a neighbor, and anyone you want to address with respect. While 'ji' is a Hindi word which is used to show respect to people, and hence, Auntyji is the more common form of Aunty.
However, the word, since used for middle aged women, is also used to tease women of lesser age, and is mostly used for women with older/not-so-modern tastes.