Can I still use light room time lapse 3 with Lightroom cc?

That's not officially supported. You will need LRT4 in order to be fully compatible with the new Lightroom.

Okay, thank you. I have LRTL3 private license . If I upgrade to LRTL4 private license, then later on upgrade to LRTL 4 professional, will it be the same price as if I upgrade one at a time as it would be to upgrade it with the cross grade?