The age limit for the UP POLICE CONSTABLE  is provided below:

• The male candidates who apply for the post should be ages between 18-22 years.
• Female candidates should be between 18-25 years to apply for the post.
• Age relaxation will be given as per the rules of the board.

Now as you are a general student you have no age relaxation rules applicable. As you are born on 5/8/1999, then you will be 23 years old by 2022, which makes you ineligible for the examination.

To know more about UP POLICE RECRUITMENT is provided below:

https://news.careers360.com/up-police-recruitment-2021-revised-dates-released-for-1329-vacancies

I hope this answer helps. All the very best for your future endeavors!