One of my friends graduated from Thapar University. According to his experience, there is no harm in attending the orientation classes
Orientation classes are held for the first-year students before the start of the academic session. They are not necessary to attend. But there is no harm if you attend them, in fact, it is of great help and a good fresh starter.
They get you to know information about the grading system of Thapar University. You get guidance about the do’s and don'ts regarding the attendance and the qualifying criteria, etc.
Apart from the academic schedule, there are guest lectures by the director, senior faculty, and by the deans. Hence, it is better if you attend the orientation session.