cruiserweight title ECW title Tag title?

You have to do it (semi-) legitimately. You can't just create a title match.

Here's what you do, on the build-up to Extreme Rules (1st PPV after Wrestlemania I believe) Edit the rankings and set:

A Tag Team you've created (whether of your own CAS ppl, or of real WWE guys, it just has to be one you created from top to bottom) as the WWE Tag Champions.(this HAS to be the new tag titles, the circle ones, won't work with any of the others....but if you have the tag titles separated between shows, you can keep that, just one show has to have the new titles).

The Miz as the #1 contender to the WWE Title (HAS to be the Cena version, won't work with any other title),

Rey Mysterio as the #1 contender for a belt (Whatever Major or Minor title you want for either show, just not the WWE Title),

A Created Superstar as the #1 contender for one of the other Major or Minor titles,

and whatever attitude team you prefer as the #1 contender for the WWE Tag Title

Sim or play your way up to the PPV making sure that those 4 are #1 contenders going into the PPV, and then if you win all 4 titles, you'll unlock 6 belts in 1 PPV
Cruiserweight for Mysterio
Miz Title for Miz (Obviously lol)
ECW Championship (WWE Version) for winning a title at Extreme Rules
ECW Championship (Actual ECW) for winning a title with a created superstar
Tag Titles 98-02 for winning a title with an attitude era team
WWE and World Tag Titles 02-10 for setting a user created team as tag champions

And obviously, if you have some of these, you can just pick and choose which title to unlock, just follow the steps and ignore whatever steps involve a title you don't care about. I figured I'd share the way I figured out to unlock 6 titles in 1 PPV (and if someone is just starting, they can do this in the first month and get off on a great foot).