There is not enough evidence to suggest Prime Minister Modi participated in Bangladesh's struggle for independence.
During his two day visit to Bangladesh, Indian Prime Minister Narendra Modi attended the Golden Jubilee of Independence of Bangladesh. At the event, Modi said that when he was 20 to 22 years old he participated in a Satyagraha for the freedom of the people of Bangladesh. Modi said that he was arrested and almost went to jail in support of Bangladesh’s Independence.
On March 26., Brajesh Kumar Singh, Managing director of Network18 Group posted an extract of Modi's book online, in which the Prime Minister recounts various struggles in Gujarat.
However, other than Modi's own statements, there is no evidence or documents relating to his time in the Bangladesh Liberation War. As such, we have marked the claim unverifiable.