Tightness and pain in right knee when i bend with crackling sound ... slight numb feeling radiating to calf muscles till foot ?

Ligamentous : This sounds like something you need to have imaged and examined by a good sports med or orthopedic doctor to see what ligament and nerve compression issues you might have.i suggest you start with a clinic appointment to have a good clinical exam, which direct the type of imaging you need to fully diagnose the problem and get to the corrective therapy best