They commonly drop the '2S' designation from such device numbers so you're looking at the 2SD2396 which is an NPN Darlington, TO-220 package, 30W, Vceo=60V and Ic=2A, hfe=1000 and Ft=40MHz.
What is the current application for the device you have?
If NPN Darlington is correct then you can use the parametric search option at alldatasheet.com to find others that match