I have extracted the contents of a DS rom, and it returned me some files with the NCGR.lz extension. How do I do to view those file's contents?
Sounds like it is a simple lz compression. Try opening the DS rom in Tinke, and you should be able to decompress and view the files in there.
d - decompress file
spacebar - view file as recognized file type
p - " " palette (NCLR)
t - " " tile (NCGR)
m - " " map (NSCR)
For NCGR files, you will need to open a palette first.
Which game is this for?
Tinke looked way too complicated, but I managed to open them with Console Tool.
It is for Giana Sisters DS