Yes the Z97 anniversary edition supports multi gpu mining. You need to start out your rig with one GPU first , see if it loads up until to windows, if it does try with 2 cards and so on. Usually with this board you will have a few problems with 6 GPU but it should support well 5 GPU-s. If it doesn't give you signal even with 1 GPU then you should have your mainboard troubleshooted. I don't know about ASRock but latest MSI motherboards have already prebuild led lights that tells you what your problem could be.

If you ask me a 6th generation motherboard should work much better for mining than a 4th generation motherboard, so if you have some money left by all means by a Z270 motherboard from MSI, it supports up to 8 GPU-s without problems.