when i open the 'maps' folder i can see 24 files (maps) but when i wanna start a new game there r only 6 maps i can chopose from... how can it be and how can i fix it?

They're split up in different modes.

Different maps for Capture the flag, Infiltration and Deathmatch (Team deathmatch, Rambo and Pointmatch).

Just choose another game mode and you'll see other maps.

Or type in the game:
/map (mapname)

And you can have CTF and Inf. Maps on DM, Inf. and DM maps on CTF, and CTF and DM maps on Inf.

oh. thank u very much!