In season 4 the episodes will switch between ND and then to New York where the graduating seniors will be. This post will be focusing on New York though. These are those who would return as main characters in New York.
Mercedes-NYU (Kurt suggested this to her and maybe she won't want to move to L.A. straight away)
Mike-His Dance College could be in New York
Santana-She is working in New York as a model because she doesn't want to start college yet.
Recurring in the New York side would be-
Puck-Visits Finn about 3-5 times during the season.
1- New Directions
Rachel and Kurt begin to get used to their new lives. Blaine misses Kurt. Quinn arrives at Yale and finds out about their glee club.
2- We Are Family
The former members of ND in New York miss Glee club but find that they can compete at college level naming their Glee club the "Titans" in honor of their former High School. Quinn joins the glee club at Yale and meets their leader who is a shadow of her former self. Finn makes a new friend.
In a search for new members the Titans prepare a flash mob to present to New York but the first day of school for NYADA students is moved up a day and Kurt and Rachel must make their decision.
After skipping the first day of school at NYADA Kurt and Rachel must make a short production based on their favorite life moment to prove to Carman that they are serious about NYADA. Mercedes is bullied by students at NYU about her weight. New members join the Titans.
5-Wind Beneath My Wings
Mercedes gets sick for unkown reasons until she finally admits that she's been starving herself to lose weight because no one likes fat stars. Rachel confronts the bullies and tells Mercedes that she is her inspiration. Finn is accused of theft but it is really his new found friend.
Rachel visits Quinn at Yale. While Puck visits Finn in New York and helps him deal with his theft issue.
7-In The Arms of an Angel
Quinn and Rachel go out hiking because Rachel is leaving on the next day. Rachel and Quinn get lost due to a storm and have to spend the night out in cave. As they try to find their way back the Titans have to face their first competetion which involves all of New York City without their strongest singer.
This would end the first arc the other competetions would be State, Nationals and Internationals. Episodes 8-12 are coming next