1.3 diesel crank nut size

[whitravis]

Before I make a 4hr trip to a tractor, what size socket to turn the crankshaft bolt? To see if engine is locked up.

 

[whitravis]

Before I make a 4hr trip to a tractor, what size socket to turn the crankshaft bolt? To see if engine is locked up.

It's a Mahendra 3215 with Mitsubishi 1.3 liter diesel.