How do I revise the full syllabus of the NEET UG 2021 in 15 days and give a mock test twice a week simultaneously right now? I’m scoring near 400.

Try to schedule your revisions around your tests. Once that you give the test, analyse the test and see what chapters you are not doing really well and in chapters you have prepared well, revise the topics that you are getting wrong. Also try to find the topics which are a little easier for you and try to prepare them if yoi have time.