What is meant by "Practice the truth thy brother is same as thou"? We are different. Our upbringing is different.Our sanskaras are different. We are made up of sanskaras therefore every self must be different. Yet Buddha says Practice the truth that thy brother is the same as thou. 
It would be great if someone can explain what is meant by the above statement of Buddha?
He is simply affirming as a truth/truism that your brother is the same as you. It's reminiscent of Jesus' "love your neighbour as yourself" -- possibly because of the (originally) Christian background of the writer Paul Carus (who wrote the 1894 The Gospel of Buddha which you're quoting).