Casteism is the correct term for this. This isn't a different race of people, it's the same race of people in a different class. I agree with you that there are many similarities between Casteism and Racism, but I think it's good to separate it out.
From what I've learned on the topic, with Racism someone sees the color of your skin and can make assumptions from there. With casteism thought it's more about your family name, as someone from the lowest caste can look like someone from an upper caste.
Reductionist approach "skin color"=="race" can be easily debunked. Could white German be ever racist to white Jew?
You have a point. But Apple doesn’t want to continuously debate caste vs. race (they’re both social constructs). For statute, it should suffice to incorporate caste as an aspect of race.
Go read up on what the caste system is, its history and how it effects life within India. It seems you'll learn something new.
Why is it just not called racism? Introducing new terms kind of derails the problem.
India (and Africa, China, Asia...) has a system where people with lighter skin are consider as "better". People with fair (whiter) skin are considered aristocracy, that never had to work outside on fields.
And castes could not intermarry for couple of thousands of years, it is legitimate to consider them as a race.