The fairing will need a lot of mods, you will have to narrow the fairing and also rebuild custom brackets. The zzr1200 fairing is designed completely different than the 600´s fairing.
With a lot of time and money you can possible get this to fit. It might be easier to create a fibre-glass mould of your current fairing and then reconstructing the sections that you want from the zzr1200 fairing, else create a mould of the 600 and then also create a mould of the 1200. After you´ve done this, combine the moulds to create a perfect fir on the 600 mould.
This is not an easy job, and a factory fairing will not fit.
You might have to get your light lenses custom made to fit onto the new fairing mould. 
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