If an Indian tourist is already in a US state that sells Powerball, can they buy from a normal licensed retailer without being a citizen? And if the ticket wins, does it have to be claimed in that same state? Just want the official rule, not travel advice.
Yes. Powerball's official FAQ says a visitor does not need to be a US citizen or resident. An Indian tourist who is physically in a selling jurisdiction may buy from a retailer licensed or authorised there, provided the visitor meets that jurisdiction's legal-age rule.
A winning ticket must be claimed in the jurisdiction where it was purchased. The selling lottery sets identification, signature, deadline and claim-location rules, and federal plus jurisdictional taxes may apply. Keep the original ticket and check that lottery's official claim page before travelling home.