I am going to speak French.
In listening to you, I get the impression that a significant part of Indian society recognizes the falsehood on which this practice of untouchability is based. You mentioned that India's founding fathers made the system of untouchability illegal under the constitution.
Why is it that, 60 years after independence, no one has succeeded in solving the problem? How would the so-called higher castes be disadvantaged if the system of untouchability were abolished? Are there major economic interests behind untouchability or does it survive only because of the strength of religious and cultural traditions?