The biggest question is what devices will you be bringing and are they locked to a certain carrier? That will determine what prepaid options you have.
If they are AT&T devices and they are locked to AT&T that will mean you'll have to use an AT&T MVNO or provider. If they are unlocked then you can use them on a T-Mobile provider too.
Just know that on prepaid your customer service will be bottom of the barrel. Count yourself lucky if you get a live person in India to help you out.
Cricket is probably your best AT&T prepaid provider at this point. They are owned by AT&T but as a completely separate company.
A lot of these companies mentioned, Page Plus, Straight Talk, Tracfone, Net10 are all owned by sleezy billionaire Mexican
Carlos Slim, and his America Movil/Telmex company. They are famous for crappy customer service.