Does anyone know if it's even possible to fit and map an IHI golf R turbo onto my mk1 vrs? I've been offered 1 for free and I'm prepared to spend on a manifold, injectors, intake and mapping if it's possible.

Highly unlikely.  You need variable vane turbos on your engine.  I highly doubt a petrol turbo will be VNT.

Not possible, as devon states it's entirely the wrong type of turbo, if you're prepared to spend then just buy a new turbo actually suitable for your engine and get it remapped properly.

Fair enough cheers for the advice boys! With it being free if I wanted I thought it was worth asking