Takes a 19mm 12-point Socket to fit the crankshaft bolt as 509vw referenced. A deep-well Socket works best.
And, after installing a known good battery as 509vw suggested, you probably ought to check the wiring at the starter. There is a big red (or black) cable that goes to the starter directly from the battery positive post.... very nearby on the starter is where the Solenoid wire plugs on. Make sure it's connection is good.......... unplug and re-plug!
Likely, if the car has been sitting for 5 or 6 years the Injection Pump, etc., may have lost fuel. So, once you get it cranking over with the starter, if it is going to start, it will be almost immediate. If not, I'd start by bleeding the injector lines at the injectors. If no fuel comes out, you'll likely have to prime everything, including a new fuel filter...
Keep us posted!