
If you are referring to Randy Jackson the American Idol Judge, no he is not a brother of the King of Pop. Although, Michael Jackson has a brother named Randy but those 2 are not the same.
Randy Jackson the American Idol Judge was Born: 23 June 1956 in Baton Rouge, Louisiana.

[photo credit: Jason Nevader/WireImage]
Steven Randall “Randy” Jackson the brother of Michael Jackson was born October 29, 1961 and is an American singer and musician. He’s a member of the Jacksons. He is the youngest among the Jackson brothers while Janet is the youngest of the Jackson family.
Above is a photo I found from getback.com