You should go for M.Sc. This is the best option after completing B.Sc.
To get admission in M.Sc. course, you have to first appear in an entrance exam. The most popular entrance exam is IIT JAM (Joint Admission test for M.Sc.).
Below are the best entrance exams other than IIT JAM through which you can get admission to MSc course.
- National Entrance Screening Test (NEST)
- MCAER CET
- GSAT (GITAM Science Admission Test)
- OUAT Entrance Exam
But you should first satisfy all the eligibility criteria required to appear in these exams.
Best of Luck!