Language and word choice can directly reflect a region's worldview, thought processes, and structure. If there is no word or direct translation to convey an idea or phrase, it is unlikely that it originated from that area.
If the caste system was an Indian construct, there would be a word in Indian languages that conveys its meaning. Caste has no literal translation in many Indian languages. This is strong evidence to suggest that the caste system is not an Indian construct. The word "caste" has been given as a loan word from the Spanish and Portuguese language family.  Numerous English and Roman languages have variations of the word "caste." The Portuguese word for caste is "casta." Castas were first documented during the late medieval period and described a social hierarchy very similar to the modern Indian caste system. Castes are used to describe hierarchies in social systems, deemed by station at birth in the case of India. The caste system makes it incredibly difficult for an individual to rise above their given socioeconomic class or intermarry. Castes are rigid and built to keep groups separate and in power.  Caste systems are characteristic of colonial societies, who assert power over other groups to stay in control. Implementing the caste system in India allowed the British to divide society and pit them against one another so that they could not rise up or fight for independence.
The caste system has origins in Ancient India from Brahma. Brahma is the Hindu God of creation. The caste system was legally formalized in Indian texts around 1000 BCE in a treaty called Manusmriti. According to the treaty, Indian social society was divided into four categories, with the rich at the top and poor at the bottom. Over time, those four categories became the modern castes we see today.
Language is the lens through which societies interpret the world. It is reflective of their values, culture, and belief system.
[P1] Cultures and belief systems are revealed through language. [P2] Indian languages do not have a direct translation of 'caste'. [P3] Therefore, the caste system is likely not an Indian construct.
Rejecting the premises