I traded into some AR10 or SR25 magazines that i'm not sure who made them. They are in a sealed heavy plastic bag.  The only markings on them are a KAC stamped into the metal on the front bottom of the magazine, and there is a K in a circle that appears to be gold colored paint over the stamping.  Now for the funny part.....included in the box was a DPMS marked magazine with the bottom looking almost exactly like the KAC marked mags, however the welding is on the opposite side of the front of the mag.  The KAC mag also holds 20 rounds, the one DPMS holds 19, but looks like i can almost force one more round, but it will not stay in.  The baseplates on the KAC mags have an M in a kind of squared ended oval stamped into them, and are black in color.  The follower appears to be plastic, and you can see the spring in a hole in the follower where it latches into the follower.   There are no dates on the mags anywhere, just the KAC and K in the circle, and the M in the squared off oval.  Also, the follower makes the first round loaded go to the left, or magazine catch side of the magazine.

My question is are these actually pre ban magazines? And where can i find this information for sure?

The kac are Knights Armament.
Best SR25 mags on the market. No way to tell if it’s preban. They are most likely not. If the base plate on the kac mag is three parts then it current.

The base plate is just one piece.  Has an indention in it where the loop on the bottom of the spring goes into, just like the DPMS mag.