Does sponsor need to be in US to file IR-5 petition?

[Maxmu]

Hi,
My son who is 16 yrs of age now is a US citizen.

I am aware that he can file for me and my wife under the IR-5 category once he is 21yrs of age.

My question is does he need to be working or studying in US (earning independent) for him to be able to file the petition for us with USCIS?

What if he is studying in India when he turns 21, do we need to wait for him to complete his studies in India and move to US first before he can file with USCIS? OR Can he file while studying in India? If this is possible, then I am assuming we will need to show bank balances, funds .etc in support of our petition?

Thanks

[newacct]

He needs to be domiciled in the US when he files the I-864 Affidavit of Support (which is at a later stage than the I-130 petition).

[Maxmu]

Thank you, this is helpful.