Be careful here... entanglement weapons were assumed to be banned in Robot Wars for quite some time while never being written in the rules.
The current Black Top rules (which Im using as the FRA rules do not appear to be available online at the moment) seem to prohibit weapons which immobilise both your opponent and yourself, which would mean nets and cables fixed to your robot at some point. If your nets and cables detach, then you may have found a way around the rules - but be aware of the rule that projectiles must be tethered.