Hello aspirant, you have already reported in the college and joined also, you have submit your allotment order in the college itself, so that there will be less issues during the admission process and all documents are verified by than. All the best

No, you don't have to report after self reporting and joining reporting. You have to join only after your admission is confirmed, and the course begins, you have to check that with the college itself, if it's possible, just report once to avoid any problems. If not, check the website of the college, and ask the management. They will definitely be able to help you. All the best!