Take-Two Interactive CEO Strauss Zelnick admitted that he’s wrestling with some nervousness around the long-awaited launch of “Grand Theft Auto 6” in November. He also addressed the turnaround at Take-Two’s Zynga and the importance of investing in original properties during his conversation at the inaugural Interactive Innovation Conference in Las Vegas. Zelnick spoke April 28 at the Fontainebleau Las Vegas with Jennifer Maas, Variety ‘s senior business writer for TV and video games. Take-Two’s unveiling of “ GTA 6 ” is expected to deliver a blockbuster performance to the company that operates a collection of major gaming labels including Rockstar Games, 2K and Zynga. “We’re blessed that we have some of the greatest creative talent on earth working inside the four walls of Take-Two and all of our affiliates.…