if u have a 6.5 speakers at 75 rms @ 4 ohms and 6x9 at 100 rms @ 2 ohms can use a amp that is rated at 75 rms @ 4 ohms and 100 rms @ 2 ohms or is it not safe
You should be good. Running the amp to the set of 6 x 9's that are 2 ohm isn't going to hurt it. Bridging it and running 2 speakers at 2 ohms would hurt it.