Elon Musk is zeroing on a new Asian production hub for his Teslas. It's not India
Considering how shitty Indonesia is, it must be something to prefer Indonesia to India to manufacture cars.
Indonesia with a population of 280 million neighbours Australia , which has around 40% of the identified resources of uranium recoverable at low cost.
The US would want to keep Indonesia in their camp and consequently integrate the Indonesians with American military and industrial supply chains. So investing there is a nice fit with US geo-strategic objectives.
Tesla will invest in India, if and when the domestic market matures and a demand arises for their motor vehicles. Though Indonesia seems to have a higher prosperity India(about double the per capital nominal GDP of India's - $4691 to $2342 from wikipedia) ,I don't think there is huge market for Tesla cars there either