Half by request and half me thinking it’d be fun.
Scott Adkins - Bruce Wayne (Batman) *As seen in Justice League fan cast*
Colin Ford - young Dick Grayson (Robin)
Tyler Hoechlin - older Dick Grayson (Nightwing)
Michael Cain - Alfred Pennyworth
Hayley Ramm - young Barbara Gordon (Batgirl)
Bryce Dallas Howard - older Barbara Gordon (Oracle)
Jonah Bobo - young Jason Todd (Robin)
Thomas Dekker -older Jason Todd (Red Hood)
Seamus Davey-Fitzpatrick young Tim Drake (Robin)
Logan Lerman - older Tim Drake (Red Robin)
Chloë Moretz - younger Stephanie Brown (Robin)
Juno Temple - older Stephanie Brown (Batgirl)
Ayush Mahesh Khedekar - Damian Wayne (Robin V)
Evan Rachel Wood - Kate Kane (Batwoman)
Shay Mitchell - Cassandra Cain (Black bat)
Gary Oldman - Commissioner Gordon
Anne Hathaway - Selina Kyle (Catwoman)
Dichen Lachman - Talia Al Ghul
While this is not for Nolanverse I did keep Alfred, Selina, and Gordon with their movie castings honestly because I just love them. Also Seamus Davey-Fitzpatrickk is near impossible to get a picture of. The one I used is a screencap from his guest appearance on Person Of Interest. However he’s 14 which is around the age Batman told Drake he was a real Robin.
Scott Adkins is an unconventional choice but he’s a good actor and his martial arts skills makes him a perfect choice.