What do you mean by maximum requirements? There is no such think. Did you mean the requirements for running GTA V at ultra settings?
In that case, I am going to give you the minimum current requirements for ultra:
* GPU (THE MOST IMPORTANT THING) Nvidia GTX 1050, AMD RX 560 or better (the RX 470 can run it at ultra 70+ FPS) but as long as you play with FXAA and MSAA disabled, you will get around 60 FPS on all cards
* CPU: Pentium G4560, G4600 etc
* RAM: 8GB DDR3 (DDR4 if posible)