Dear aspirant, as per the DU guidelines, it is compulsory to attain the attendance of 66% for being able to appear in the exams, else you are not allowed to sit for the exams. For students having below than 44% of attendance, the students have to take fresh admission next year. So you need to apply for a fresh admission. Rest it depends on the college authorities there is a chance that they consider your previous year's application. There are strict rules only for 1st&2nd year not for 3rd year students. You will be debarred from exams but you can take a fresh start.

All the best.