To OP :)
What I would suggest If you haven't already done this, is be able to demonstrate to these groups you're trying to join, that you are raid ready.
Being raid ready means:
You have upgraded your gear as much as you can pre raiding.
You can show you've read guides and done research on your job and know it inside out.
You can commit to a time schedule and show up on time and prepared
You've done research on the fights and know your role in that fight.
That you have a positive attitude and can work in a team with others.
For all I know you've done all this, but from my experience many people lack these basic raid etiquette, basically just from lack of experience.
Filling these prerequisites will give you a good leg up on getting into a raid group.
Good luck!
