That's not an RG, it appears to be an EX350 body model year 1993 most likely.
And to answer your question, yes it's a real Ibanez however an RG neck will not fit it. The AANJ EX guitars have a fairly different bolt pattern and only an AANJ EX neck will fit. They pop up on the 'Bay every now and again.
If you are starting a body from scratch then there are a couple of things that you can do. You could try dabbing a little chalk dust around the neck holes and pressing the heel into the neck cavity to mark the new hole. You could just drill new hole sin the body and plug and redrill the neck holes.