is it possible to get location via a cellular network if the device doesnt have a data plan? is it possible to get location via a cellular network if the device doesnt have a data plan?

or does it need a data plan to be able to get location via a cellular network? 

is a data plan needed to get location via a cellular network?
Yes, that is possible without a data connection by e.g. using UnifiedNLP and a corresponding location provider. I e.g. use the LocalGsmNlpBackend, which downloads a selection of the OpenCellId database (for the area I need) to the device for local usage. That database contains the positions of cell towers. As you are booked into at least one of those, your coarse location can be estimated. Add another location provider which is e.g. WiFi based for more accuracy if you wish. Apart from downloading the data (preferably while connected to your home WiFi), this works completely without a data connection.

Make sure you pick the correct UnifiedNLP package, depending on whether your device has the Google framework installed (stock ROM usually has this, or if you use a custom ROM but have GApps installed) or use a custom ROM without GApps.

For a more detailed description, please see my article Android without Google: microG, which discusses the variant on a device without Google framework.