the EOTech is meant to mount directly to an A3 type mount, aka the M1913 Picatinny rail. if you have a fixed carry handle or just want to mount it above the carry handle, you'll have to get an adaptor made for such or the gooseneck mount as pictured above which will allow you to co-witness your optics and irons. check Brownells, ARFcom, etc. there are tons of them.
Bobby
ETA: you can also replace your stock handguards with a 4 rail system and mount it to the top of the handguards.