This is just nonsense. Hindi has nothing to do with caste system. Hindi was promoted because of the need for a common language for a nation with 300+ official languages (not counting the dialects) - as it's the language that is most commonly spoke and understood. It's again absolutely nonsense about BJP/RSS. In the recent times the only party that worked for the poor/lower castes/class is BJP. Most regional parties works for the dominant upper castes and congress further discriminated against the dalits/STs during UPA2 with their legislations (and always been the party of upper castes + muslims and christians).