I need to know where the crankshaft position sensor is located on my jeep grand cherokee

Crankshaft position sensors are located on the engine near the intersection of the transmission and the engine, or near the crankshaft on the other side of the engine.

I need a year,make,model, engine size to go further.

The crankshaft position sensor is located around the crank. Look for a stubby piece of plastic aimed at the edge of the crank pulley. The crank pulley is in central pulley which all the belts are ultimately driven from. It will be in the center-line & bottom of the front of the engine. Typically they are ~45deg off to a side. It's possible you may not be able to remove it without first removing the crank pulley.