 The producers considered Danny <unk> for the role of bandit chief Gabbar Singh , but he could not accept it as he was committed to act in <unk> Khan 's <unk> ( 1975 ) , under production at the same time . Amjad Khan , who was the second choice , prepared himself for the part by reading the book <unk> <unk> , which told of the exploits of <unk> dacoits . The book was written by <unk> Kumar Bhaduri , the father of fellow cast member Jaya Bhaduri . As cast members had read the script ahead of time , many were interested in playing different parts . <unk> was considered for the role of Thakur Baldev Singh , but Sippy thought Sanjeev Kumar was a better choice . Initially , Dharmendra was also interested to play the role of Thakur . He eventually gave up the role when Sippy informed him that Sanjeev Kumar would play Veeru if that happened , and would be paired with Hema Malini , who Dharmendra was trying to woo . Dharmendra knew that Kumar was also interested in Malini . Sippy wanted <unk> <unk> to play the part of Jai , but there were already several big stars signed , and Amitabh Bachchan , who was not extremely popular yet , lobbied hard to get the part for himself . 
