There is a uptown (6)<6> skeleton in development by Lexington456, nyctrman, and myself. The downtown (6) is a temporary skeleton until the finished (6) by Lexington456 is completed. There is a possibility of having a downtown (6) via the (4) to Crown Heights. Here is some progress. I will post pictures later.
Uptown Service
(6) - Construction completed up to 3rd Av-138 St
<6> - Construction completed up to Hunts Point Av
Downtown Service
(6) - Construction completed to 125 St. It will go express before 14 Street to head to Crown Heights.
<6> - Not in development at this time.