Hello kiran

campus placement is conducted many steps.

first college will decided .how many number of student are qualified company eligiblity criteria.

company Hr will come in college to give a short presentation about company and package and job location.

first screening round 

Apptitude reasoning and some techanical question according to branch. those student are qualified these round selected for second round.

group decision(optional depend on company)

final round 

personal interview

those student are cleared these round .who selected  for job .