Which group introduced and developed the caste system in india

The caste system in ancient India began after the Indus Valley Civilization disappeared and new people from the north arrived, the Aryans. They brought new ideas, such as Hinduism, which is now a world religion, and the idea of a caste system. A caste is a social group into which a Hindu is born. There were four social classes within the Aryans: the priests & scholars; the warriors & nobles; the artisans & merchants; and the lower level, farm workers,  and servants. If a person was born into one caste could not move or marry out of their caste. The caste system wasn't part of Hinduism at first though it began at about the same time as Hinduism. When Buddhism began in India, Buddhists did not recognize castes, which made Buddhism attractive to the lower ranks in  society but regardless of the introduction of Buddhism and other religions, most ancient India people remained Hindu, and as a result, the caste system continued.

it is a part of john locke's natural rights popular during the age of enlightenment that people had inalienable rights to life, liberty and property. this was reflected by thomas jefferson in his declaration of independence as rights to life,liberty and the pursuit of happiness.

another line in the declaration of independence is that people have certain rights just because they are human. humans are capable of obeying the three natural rights john locke mentioned making them governable by these laws and therefore entitled to these rights as well.