I've told an friend of me he should download the battlefront extrem patch. but he says that he can only play as RC and for a RC you need points he can't get this problem he has also at Atack of Geonosis.

... What???
Try to formulate the problem a bit better. If there's a bug in BFE, it can't be fixed anymore.

if he starts bfextrem and than if he select a person he only could select the republic comando but for this charakter you need points and this points he can't get because he has no other soldiers like the roketman but on my computer it works.

then something must have gone wrong with the installations...

I'd try uninstalling BFX and reinstalling a different copy of the mod first. If that doesn't work, then I'd try installing the mod on a fresh installation of SWBF2.