This topic probably has been answered before but I have seen some conflicts even in these threads and the rule book isn't clear (at least to me).

When defending against regular attacks do you get to cancel crits first or regular then crits? I have been to 2 different tournaments and both had different info..

Thank you in advance for the clarification.

This is why FFG say you need to bring your core set to a tournament.

The core set contains the basic rules.

Page 12 of the core rulebook

6. Compare Results
During this step, players compare their dice results to determine whether the defender was hit.
To determine whether the defender was hit, compare the number of [evade], [Hit] and [Crit] and results in the common area.

For each [evade] result cancel (remove) one [Hit] or [Crit] result from the attack roll.

All [Hit] results must be canceled before any [Crit] results may be canceled.

Autoblaster and Autoblaster Turret can allow crits to be canceled "first" (because you can't actually cancel the hits "second"), but those are specific cases.