Hello aspirant!

As you have mentioned that you did not give your compartment of chemistry subject on scheduled time

Yes you can pursue your class 12th again from the same  school you had done it before for that you have to consult with your school staff to register you for new fresh session of class 12th

After your fresh registration for academic year 2020 you will be treated as a new Class 12 student and you will give all your exams at the end of 2020 and if you will clear your class 12th that time thereafter you will get a new marksheet of your class 12th result with no any information of compartment

CBSE  releases the registration dates every year for a fresh and a newly admitted students so you can register yourself as a part of a fresh batch of 2020 then after your registration you can pursue your class 12th again

Hope I have resolved your query in case of any other doubt you can get back to us