What kind of defense actions can you take while rigging?
You can take all defensive actions you can take while driving manually, remote controlling via AR or remote controlling via VR.
Or are you asking for defensive actions that you may
only take while specifically
rigging?
* When the condition monitor of the vehicle you are jumped into is completely filled you may spend a point of Edge to operate the vehicle for another combat turn (normally it cannot be driven any further) by taking the
Hold it Together Baby-action (R5.0 p. 176)
* While jumped in you may spend a point of Edge in a combat turn to keep the vehicle under control (instead of making a Piloting Test) by taking the
Zen Control-action (R5.0 p. 177)
* While jumped into a drone you may act as the assistant to the attacks of all your drones for the remaining of the combat turn as long as your drone is within 10 meters of the target by taking the
Swarm-action (R5.0 179). The best defense is a good offense?
do you use the full defense action or do you use the evasive driving (defense) action?
Unless explicitly specified you use the same actions, skills, attributes and limits no matter if you are driving manually, remote controlling via AR, remote controlling via VR or jumped in.
With a vehicle (or drone) under your control you defend against attacks with Reaction + Intuition [Handling], but (except against ramming attacks) you may spend a Free Action and 10 Initiative Score to add your Intuition Rating to the defense pool to dodge attacks by taking the
Evasive Driving-action (SR5 p. 205).
Can you also dodge, parry and block?
No.