Potentially a what if with a rather grotesque or at least crapsacky result. I can only imagine two places where this can be possible :
1) North Kalimantan/Borneo. Either Sarawak or Sabah. It'll be fun if this happens out of a Jewish James Brooke, the coolest way we can get it. If it is indeed a Jewish *Brooke, then he'll going to run into interesting times reconciling native traditional polities with the Jewish settlers. If he doesn't have as much admiration towards the local culture as OTL Brooke, then the only way I can see it happen is through foreign sponsor to deliberately create a Jewish homeland. It will get apartheid-y quite sooner then OTL Israel.
2) Papua. The only way would be through settlement plan not unlike Uganda Plan, only it actually comes through. It won't likely be an enticing idea for the Jews worldwide, unless it's a heavily deliberate project backed by a Freeport like mega company that uses Jewish Homeland building as a vehicle for their money making scheme. Or, this Freeport equivalent company can very well be Jewish, with both profit and ideological motives, and wants to kill two birds with one stone by this. The fate of natives here look grimmer then option #1, likely to make Indonesian treatment IOTL looks pretty compassionate.
I considered some alternatives, like Southern Sumatra(Palembang or Jambi) or Nusa Tenggara, but it seemes neither are good enough locations geopolitically for such state to culminate, and they are also far from as "empty" as both options above. Southern Sumatran Malay states like Palembang or Jambi had a tradition of integrating immigrants like Arabs and Chinese into their society and giving them a role in local politics, which makes Jews a potentially cool addition to the mix but not quite what this thread is about. Minahasa in Northern Sulawesi can't seem to be replaced or overlayed by Jewish settlers. But IOTL they converted to christianity and adopted Dutch culture so imagining they do that with Judaism is certainly tempting. It still will need a foreign patron and again, not quite what this thread is about.
I don't see neither #1 or 2 will have a particularly friendly relations with surrounding countries. #1, if headed by a Brooke like personality, will have a chance to look half good at least. Something a kind to how Sarawak and Sabah are today under Malaysia, only with Jews rather then peninsular Muslims and Indonesian immigrants. I wonder how their religious policy towards the native will be. Both Islam and christianity can serve as potential channel for subversive expressions against the state. Will they tend to discourage the spread of those religions ? Will they actually try converting the Dayaks to Judaism ? I find the later quite unlikely. As for Papuan scenario, I simply can imagine nothing good. They can't quite swarm the place like Indonesian transimgrants(which don't really outnumber the natives all that much), but the racial policies will be very draconian, likely more so then South Africa. And that this state will likely revolve around mineral exploitation of the land really doesn't help.
Thoughts ?