God is kind of real. It is more accurate to say that God is all realities, but it's quite hard to express these kinds of things in words with any applicable meaning.
To understand the answer, you have to understand the question first. The question uses three words, and each of these words can be heavy and confusing. 'To be' or 'to exist' is highly philosophical and hits at the limitations of words right away. 'God' is a concept that is used very ambiguously by people since everyone has a different vision for God.
The real problem is the third word: what it 'reality'? A reality is an understanding of the world and an approach of how to live in it. Everyone has their own viewpoints and understanding, and therefore everyone has their own version of reality. Basically, real is what you believe is real. If several people agree on a particular reality then it is called 'consensus reality', and if this agreement is based on scientific rigor, then it is called 'objective reality'.
With these things explained, let's get back to the question: is God real?
The god that you envision within your own reality is just that - a vision. However, the same can be said of yourself; that you are just a vision in God's reality. God is not so much IN a particular reality as he is the wholeness which allows different realities to exist. God is real and God is not real (depends on how you look at it), but mostly God is just beyond the concept of reality.