It's hard to know unless you have more information whether this 'regularizada' means that the version of the statement of defence has been corrected to make it compliant with the regulations or procedures (one meaning of regularizar - to make something that was irregular regular, or rather non-compliant compliant), or whether this simply means that this is the version that has been officially registered/recorded ie the official version, in the sense that first you deliver a statement of defence and then it is registered/recorded or becomes the official version once it has gone through the requisite checks.

I think that in this case, it's worth being safe. The 'versión regularizada' is clearly the one that's going to count for the case, rather than any previous/original versions, so I would call it the 'officially registered/recorded' or 'official' version.

I wouldn't used 'regularized' for 'regularizada' because in Spanish it has broader meaning than in English and it's a little clunky in English because you would generally only see the word as a translation of 'regularizada' or 'régularisé' from the Spanish/French, or in the sense of making something a regular occurrence.