Currently there are no 5th Generation IRT routes available for download. The closest are being developed on around the forum.
For real, you still have the 2 line, which is as close to real as you'll get, asthetic-wise. The most realistic fictional route would have to be the Metro Transit 8 Line by TJay1724, although there are still a few fictional IRT routes lurking around the internet which I will find links to, later on.
BStyles
BStyles