Hello dear  student!!

First  of all don't  panic  for this.

With 85.3 % marks, it is very difficult for you to get admission  in the top college of Delhi University offering microbiology and biomedical sciences,  specially  when you belongs to General category. But there can be chances that in the last 7th- 8th merit lists, you  might get admission  in some non famous colleges of Delhi University. So just visit the site regulary and get up to dated with the merit lists for admission.  Meanwhile, what you  can do is just get entolled in some other(relatable) course to secure your seat specially  if you're  getting it in North campus's colleges such as Zoology  , botany, life sciences, etc. As you  can't  afford private University  and at the same time you  just can't  waste your whole year, so it's better to secure a seat in other  courses for a safe side. But if you are only interested  in microbiology and biomedical  sciences,  then you can go for some other governement universities  of states such as Kurukshetra  university  (Haryana), Punjab University (Chandigarh) , etc.

Hope this will help you!