Hello Harish,

To get admission in foreign universities such as Harvard University, Stanford University and Oxford University, you wil have to give GRE and TOEFL exams.
They also take into consideration your CGPA during your graduation years. These universities require you to be in the top of your classes.
Since your CGPA in your graduation has been very low, you will have to score very high in exams such as ACT, SAT, GRE and TOEFL.
You might find these links useful for yourself.

https://studyabroad.careers360.com/news/harvard-university-pg-admissions-2017-219841

https://studyabroad.careers360.com/news/stanford-university-pg-admissions-2017-215432

https://studyabroad.careers360.com/news/oxford-university-pg-admission-2014
I hope this answer you will find useful.