parents Visa rejected at Chennai 3 times

[satya98]

Hi,
My bother and I live in USA, we have sent papers to our parents to visit USA, for some unknown reasons their visas have been rejected. We have tried 3 times in the last 3 years and every time it was rejected. Can some one help what we can do in this situation, we wanted to try again this year. I really appreciate any help you can offer. Can we request help from congressman?

Regards
Satya

[Manav]

Briefly

Would need to know what questions exactly were asked in interview from your parents.