NASHVILLE—The decision looms over Vanderbilt basketball these days.  Will Tyler Tanner stay and work to cement a legacy as one of Vanderbilt basketball’s greatest players of all time while working to boost his stock? Or will he stay in the draft and make his NBA dream come true right now?  Most of the offseason word has been that Tanner is more likely to return for a third season at Vanderbilt than to keep his name in the draft, but Tanner has been intent on going through the process and has kept the door open to everything as a result. He declared for the draft on deadline day and is likely to ride out his decision until the deadline to drop out.  “When you step back and look at it, it's like ‘wow, like, I get to decide on an agency and I get to think about the future a little bit,’” Tanner told Vandy on SI during the NCAA Tournament. “I'm very thankful that I can make those decisions.” The indication is that Vanderbilt has incentivized Tanner heavily to return, though.…