Hello aarnav, it is not like that you are stating. The professor give the geniune results/marks to the students. There exist some eligiblity criteria for sitting in interviews of some companies, if you doesn't meet the eligiblity criteria then you will not be allowed to sit in the interview. But there exist some companies which let the 5-6 cgpa students to sit in their interviews. If you have to achieve good placement then you have to study hard.