Inviting in-laws on B2 visitor visa

[ludlowav]

Hi,

I am working on H1-B and I am planning to invite my father-in-law,mother-in-law,brother-in-law this summer on tourist visa B2. My father-in-law is working as a govt employee.My mother-in-law is a home-maker.My brother-in-law is studying in school and he is 12 years of age.What documents do my in-laws need to carry to US embassy to show family ties in India? Also what specific documents do they need for my bother-in-law since he is studying in school?

Thanks in advance for your help!!