Yes, you still need the resistor when LEDS are in series.
The resistor value will be smaller than the 1000 ohms you would have with just one LED.

Regarding your comment re: the LED "sees" 6 volts and will blow, the same comment could be made that a single LED circuit "sees" 12 volts.

The resistor in both cases reduces the "unsafe" 12 volts voltage to a safer one.