As per the information available online, if you have submitted your application then after that you can't change information. As a result you have no options left. See its not much of a problem, but it can create issues during document verification so I would recommend you to contact the Uttar Pradesh Police Recruitment and Promotion board and get it discussed they can guide you out if any options available.

For the contact details copy paste the link below on your browser:

http://uppbpb.gov.in/Contact.aspx

To know more about UP Police SI visit the link below:

https://competition.careers360.com/articles/up-police-si-syllabus

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