can your location still be tracked on find friends while youre on a phone call

Well that depends on many factors.

Wether or not your carrier supports data access while on voice calls (some don't), whether you have Find My Friends activated, and have it allowed in Settings->Privacy->Location Settings->Find Friends to use your location, and whether or not you have set Find My Friends to show your location (i.e Not Hiding) etc....

If you have this setup, and allow everyone to know your location, and your carrier is one that suppots data while on calls, then yes. You can be tracked while on a call. Being on a call means nothing really to location services.