How to do a search for an applicant name?

If you are looking to search an applicant out from your form submissions, then you just need to access the submissions page of the form and use the search bar:

https://www.jotform.com/help/269-How-to-view-Submissions 

If you are looking to create a form that you can use to search an applicant online, then please kindly explain further your requirements. How that search tool works, etc. If you have a sample form, please share it as well.