How do you bypass the google account on an RCA RCT6873W42 Android 6.0 tablet?
So now it's saying enter the last account that was synced but I cant because I turned it off.     


You need to remove all accounts before you factory reset! Just enter the last account used on the device to start again.   


It's locked to the last account for security reasons ( Eg.  stolen and hard reset devices )    
You'll need to type the exact credentials that you last used on the device to unlock it   
Sync settings have nothing to do with the extra device security features