Its not controversial to say that right wing extremists exist, some of which even commit violence, so your analogy isn't the brilliant whataboutism gotcha that you intended it to be.
So yes, just like some very far right people exist, that can justifiably be called terrorists, so to do some very far left individuals.
So yes, just like some very far right people exist, that can justifiably be called terrorists, so to do some very far left individuals.