Apple's FY2019 revenue in India was ₹10,538.3 crore ($1.50 billion),[1] which is 0.58% of its global revenue of $260.17 billion.[2] India has a growing smartphone market, but it does not yet have a large market for Apple products.
I don't know, the growing wealth is still a good way off from becoming a ground for Apple to become very popular. Especially since the market has been heavily invested in Android devices due to the pricing disparity, it's a big jump and likely not one that can be alleviated simply by waiving some of the extra costs by manufacturing locally.
The most popular phones sold in India are low-midrange devices in the USD $80-400 range. It'll take quite a push from both the public and Apple to bring sentiment to a situation where Apple products have appeal. As it stands I'm not sure the demand will ever be there.
1. https://tech.hindustantimes.com/tech/news/apple-india-s-reve...
2. https://www.statista.com/statistics/265125/total-net-sales-o...