Goa University has a different system to calculate the marks and percentage of a student.
The aggregate of your last 4 semesters is considered and an aggregate percentage is calculated as - {(5+6)/2 +7+8)}/03
Next, you need to be at the top among all the colleges that come under Goa University- GCE, PCCE, DBCE, RIET, AITD and not just the one where you study.
If you top among all the branches of these colleges, then you will be presented awards at the convocation. Although not all the toppers get a gold medal, so you need to check with your department if they have it or not.
It is up to you and not just about getting the gold medal. It is about gaining knowledge, your growth, and making sure that you plan your career and get a job of your interest.