Hey there

If you want to complete 20 PCB chapters till 20 October of this month then that will be very difficult but you can easily complete your syllabus before 4-5 months before neet 2021. For daily schedule I'll suggest that you should not bound yourself with time that you'll have to study maths at 6 am then physics for 2 hours like that because honestly it doesn't work. So fix a target of a day like a topic which you want to complete then complete it within the time limit no Matter how much hours you'll have to put but first you should complete. Then you'll see steadily you'll finish your syllabus soon.

Good luck