Khan was born on 22 October 1942 in an ethnic Afghan Pashtun in Pishin, Balouchistan. He is the son of Abdul Rehman Khan who was from Kandahar while his mother was Iqbal Begum from Pishin, Balochistan. He had three brothers Shams ur Rehman, Fazal Rehman & Habib ur Rehman who all died before he was born.
At the age of one, his family immigrated to Bombay and started living in the crime infested slums of Kamathipura . He enrolled in a local municipal school and later in the Ismail Yusuf College after which he obtained a master's diploma in engineering- (M.I.E.) from the Institution of Engineers (India) specializing in civil engineering. Between 1970 and 1975, he taught at M. H. Saboo Siddik College of Engineering in Byculla as professor of civil engineering.