Barry
No.
Indonesian
Punahou School in Honolulu, Hawaii
1946
Hawaii
I haven't seen any credible sources that mention he had a college nickname. In high school, he preferred "Barry" to Barack. But by college, he was using his birth name (Barack Obama) again. By the way, you may have seen some online claims that he was registered as a "foreign student" or that he was called "Barry Soetoro" at Columbia. Both assertions are false.
Yes, at the Punahou School, a private school in Hawaii.
He was an excellent basketball player who specialized in making shots from a long distance, so his team-mates gave him that nickname.
Actually, it's "Barry." He went through a period of time in high school when he wanted an American-sounding name, so he changed Barack into a shortened version and it became his nickname-- "Barry." But he stopped using it in college and went back to his real name, Barack.
He graduated from the Punahou School in Honolulu, Hawaii in 1979.
I believe it was President Barack Obama :)
President Barack Obama's high school basketball number was 23. But this was before Michael Jordan made this number famous.