There has been a lot of rumors going around about who will play Green Lantern in the Justice League or solo film and even if he will appear in the DC TV universe. One thing that seems to be the general consensus is that it will be the John Stewart version of Green Lantern.
The 2011 film featured GL Hal Jordan, played by Ryan Reynolds, the movie was considered a flop but at first it was thought they may still keep Reynolds as GL in the DC Movie universe. But Reynolds seem to not want to reprise the role and there was questions how they may tie that film to the Man Of Steel storyline going forward.
When DC/Warner Bros announce Batman V Superman film and that it would lead to the Justice League talk was who would play who. Nearly all the major players have been named with one exception Green Lantern. It has not been said which version would be in it or who would play him.
While that has been going on other rumors surfaced that GL could appear in DC's TV universe, they have steadily been adding characters from the DC comic universe into the Arrow/Flash shows and other spinoff's are planned and with the movie and TV universes being separate there is the possibility the same characters could appear in both.
While DC/Warner Bros haven't made any announcements rumors have surfaced some by the fans but some by the actors looking to or possible playing the character, for the movie universe Dwayne The Rock Johnson made comments to it before it was said he would play Black Adam in Shazam, Idris Elba has been a fan favorite but he is contractually obligated to Marvel and can't play a DC character, Tyrese Gibson has made a major push via social media and posted a number of pics of himself as Green Lantern.
Mow even the TV universe GL rumors are picking up, David Ramsey who plays John Diggle has given fuel to the rumor that Diggle is actually John Stewart, although Ferris Air has been mentioned which has to do with Hal and not John. There has been rumors of GL in the TV universe for a while.
One rumor that hasn't fit to this is Nathan Fillion possibly being GL he would play Hal most likely if the rumors were true, which could fit with a rumor of an older seasoned GL in the Justice League.
While they should really keep closer to the comics in whatever they do so they can build the Corps up but it looks like they will go a different direction to distinguish it from the 2011 film which isn't such a bad thing especially since it's part of a bigger cinematic universe.
We'll have to see what DC/Warner Bros decides which hopefully will happen soon, until then will have wait patiently.