Utilizing terrain to block LOS during deployment is the only defensive option a Netrod has.
If used alongside Jumper units (Arjuna and Proxies), they can 'save' those models orders if all the models themselves are taken out of action. This means that your Netrod can become a useful order battery and sponge against an aggressive piece trade.
Utilizing infiltrating models to counterdeploy Netrods is an option, or shooting one one your way to accomplish an objective, which doesn't have a high opportunity cost. You're already moving towards an objective, if you remove a regular order on the way it's icing on the cake.
Unless you have no other option with an order, I recommend ignoring the Netrods. If you have the option of potentially killing an actual model or killing a Netrod, taking a model from your opponent is a much more efficient use of orders. If every other model in the combat group is dead, the order the Netrod provides doesn't do anything, and because they are considered equipment and not troops, your opponent cannot move a Netrod into a different combat group.
Remember too that your minesweepers can 'steal' the netrod to add an additional order to one of your pools. Don't go out of your way to pull this trick off, but if you have someone nearby to try it on then it's a major morale blow to your opponent.
Netrods require zero support, so work in any list with a few spare points.
Netrods have the AI Beacon special rule, forcing them to drop onto the battlefield. Keeping the Netrod close to the center of the board protects from scattering off the board, but makes them vulnerable to your opponent killing them before you can take advantage of the order it provides. Putting a lot of terrain between your opponent and your Netrod discourages spending orders trying to remove a single order from your order pool.
Active Turn Role
Netrods can not take actions in the active turn. Their singular role is generating a cheap regular order for another model to use.
None. Netrods can not make ARO's