Engineering has become a prerequisite in India and many families or students opt for the Engineering degree. To be frank it is not that easy to clear engineering and one needs to be dedicated, focused and should have an interest in the subject.
As per my understanding, Engineering is a 4 years full-time course and the university allows you the grace of 4 more years to clear your backlogs and get your Degree certificate. It means that one needs to complete his engineering degree in a span of 8 years. These eight years includes the day you joined the college. In your case, you have joined the college in the year 2013 and when we add 8 years from the date of joining, it gives 2021. So, you need to clear all your backlogs (all theory, practical, assignments, internals, internship, project works, etc) by June 2021. If you are not able to clear the backlogs within the given 8 years, the university would give you university issue an NFTE (Not Fit for Technical Education) certificate. I would suggest you focus on your backlogs and try to complete all the remaining papers and other contents and complete your engineering degree by the stipulated time.
As you have discontinued your classes but you have completed your regular 4 years of engineering course in college, so you just need to fill in the examination forms at the correct time and prepare for the exam. You need not attend the regular college as your regular college was attended provided you have the required attendance. If there is any problem, contact your college or HOD and seek guidance.
Limit your "alway's" and your "never's." - Amy Poehler??