Punished on Dentarg/Tarren Mill could be the place for you. We have people who are interested in m+, just the lack of a dedicated m+ tank(s) at times is a stopper at times. We are not actively looking for raid tanks, but a sub when one of our MT is away would be awesome as well. I know that the post of ours (Punished is looking for more raiders) doesn’t list any melee(s) to be recruited, but regardless of that we are opened to all and relatively flexible with what people are doing.
Punished is mainly raiding focused guild, with m+ being more of a side thing on off nights and weekends/evenings. (Raid nights are Wed/Thurs 21 to 00 ST / m+ any other time)
We’re all mature, older, chill and enjoy doing things with a pace that matches people rather than going all out while pushing the weaker out of the way.
Besides that we do not require you to join us or be even from the same faction as we accept cross realm members and even alliance 
and when you think we are a fit for you then you are free to transfer/join the guild.
I will leave my discord here Mari#6813 if Punished is something you wish to try out in your in game journey and want to know more.