did he ever change his religious faith?
Yes, he accepted the Three Refuges and Five Precepts from a Buddhist monk in the traditional manner
B. R. Ambedkar
After meetings with the Sri Lankan Buddhist monk Hammalawa Saddhatissa, Ambedkar organised a formal public ceremony for himself and his supporters in Nagpur on 14 October 1956. Accepting the Three Refuges and Five Precepts from a Buddhist monk in the traditional manner, Ambedkar completed his own conversion, along with his wife. 
who received the bharat ratna award in 2017 UNANSWERABLE what is bharat ratna? The highest civilian award of the Republic of India. when was it introduced? 2 January 1954 has it ever been criticised? The decision was criticised for awarding Ramachandran before independence activist B. R. Ambedkar and Vallabhbhai Patel, who were bestowed the honour in 1990 and 1991, respectively. who was the second person? He was an Indian jurist, economist, politician and social reformer.
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B. R. Ambedkar [SEP] Conversion to Buddhism
In 1955, he founded the Bharatiya Bauddha Mahasabha, or the Buddhist Society of India. He completed his final work, "The Buddha and His Dhamma", in 1956 which was published posthumously. After meetings with the Sri Lankan Buddhist monk Hammalawa Saddhatissa, Ambedkar organised a formal public ceremony for himself and his supporters in Nagpur on 14 October 1956. Accepting the Three Refuges and Five Precepts from a Buddhist monk in the traditional manner, Ambedkar completed his own conversion, along with his wife. He then proceeded to convert some 500,000 of his supporters who were gathered around him. He prescribed the 22 Vows for these converts, after the Three Jewels and Five Precepts.