Hello,
I feel that it is my duty to inform you that there exist many free apps for iOS and Android, as well as web apps, to track IMEI locations. I am not sure what this project is supposed to be, do you want to create a program to track the phone through the console or on desktop. In this case, I can help as I have prior experience in the field. Just a head's up, achieving consistent city-level accuracy is sadly not possible, and anyone that says it is is lying. Some places may have weaker signal, fewer towers etc., and thus result in a worse and less accurate reading. In some places it is also illegal (or at least it used to be) to track IMEI numbers, even when used for personal reasons, so you might have to look into your local laws for that. Hope this helps!
Best regards,
David Marjanović