how or any app that can block users from removing apps? We are planning to give 19 employees smart phones running Android 6.0. Keeping the story aside, we want to install one application on the phone that must not be removed at all. The application simply sends map coordinates to a cloud when our employees go on out reach program.

I am told rooting the devices is the only option but they are brand new and i am sure rooting comes at a security risk (as i have being told as well). So, I was wondering if there is a way to guarantee the application will never be removed and will run no matter what?
Third party apps can help you to prevent uninstalls.
Have a look at this answer: https://android.stackexchange.com/a/21496/98689