Jain Global is striking a deal to return investor capital and manage money exclusively for Millennium Patrick McMullan via Getty Images Jain Global is pivoting to manage money exclusively for Millennium, its founder's former employer. Jain Global will return about $6 billion to investors. The deal gives Jain Global access to Millennium's resources to accelerate its growth. In a surprise move, one of the largest hedge fund launches in recent memory is returning money to its investors and striking a deal to invest exclusively for industry titan Millennium Management. Nearly two years after launching with $5.3 billion in commitments from high-profile investors, Bobby Jain's multistrategy firm, Jain Global, is pivoting to manage money for just one client, Jain's former employer, Millennium, according to an internal memo from Millennium seen by Business Insider and sources with direct knowledge of the deal.…