Required documents for PIO card

[immihelp]

I was looking for PIO card info on your site
I was asked if the applicants grand or great
grand parents are permanent residents of india
In that case provide the proof of residence.
What do we need to submit for the proof?
can you give me some choices
Do i need to get some bills of my father from india?

[immihelp]

ration card, light bill, phone bill etc.