My son (6 years old) is in India with grand parents and I am in USA with my wife and we both are on H1 visa.
My son had H4 visa stamping (was in USA in 2014 and 2015) which was already expired in last year, now we wanted to apply for his H4 extension along with my parents visitors visa.

Please let me know the required documents which i need to send from here (USA) for their visa stamping and travelling.