Question

tell me what dr.ambedkar ji has done against caste system (in punjabi)

Answer 1

The Indian caste system is a system of social stratification and social restriction in India in which communities are defined by thousands of endogamous hereditary groups called Jatis.
Jatis /Varnas
The Jatis were grouped formally by the Brahminical texts under the four well known categories (the varnas): viz Brahmins (scholars, teachers, fire priests), Kshatriyas (kings, warriors,law enforcers, administrators), Vaishyas (agriculturists, cattle raisers, traders, bankers), Shudras (artisans, craftsmen, service providers). Certain people like foreigners, nomads, forest tribes and the chandalas (who dealt with disposal of the dead) were excluded altogether and treated as untouchables. Although generally identified with Hinduism, the caste system was also observed among followers of other religions in the Indian subcontinent, including some groups of Muslims and Christians, most likely through cultural assimilation over centuries.
History
There is no universally accepted theory about the origins of the Indian caste system. The Indian classes and Iranian classes (“pistras“) show similarity, wherein the priests are Brahmins, the warriors are Kshatriya, the merchants are Vaishya, and the artisans are Shudras.
From the Bhakti school, the view is that castes were originally created by Krishna. “According to the three modes of material nature and the work associated with them, the four divisions of human society are created.”
Social Reforms
There have been challenges to the caste system from the time of Buddha, till then several thinkers discussed and opposed this Jatis/Varna sytem. We will discuss here only three thinkers Jyotiba Phule, Mahatama Gandhi,  Dr. B.R. Ambedkar and Bhagat Singh.
Jyotiba Phule
Born: 11 April, 1827
Died: 28 November,1890
Contributions
Jyotiba Phule was one of the prominent social reformers of the nineteenth century India. He led the movement against the prevailing caste-restrictions in India. He revolted against the domination of the Brahmins and for the rights of peasants and other low-caste fellow. Jyotiba Phule was believed to be the first Hindu to start an orphanage for the unfortunate children. Attack on the sanctity of Vedas Jyotirao Phule’s critique of the caste system began with his attack on the Vedas, the most fundamental texts of Hinduism. He considered Vedas as ‘idle fantasies’ as ‘palpably absurd legends’. He considered Vedas a ‘form of false consciousness’