Visitor VISA for Parents and Sisters

[kittu1only]

Hello,

I am planning to apply B2 Visitor VISA for my parents and two younger sisters in India. My concern is one of my sister is married and my other sister is not married and she is working in a company in India.

1. Should I send them all together for VISA interview or should I send my parents and Sisters separately?
2. What are the chances of approval if send them all together?

Please advise.

 

Thanks