We dont really need to pin this thread, imo. However, it is paramount that everyone knows that mapping discussion forum is not for modding queues and asking for people to take a look at their maps/asking for maps to be created, etc.
As for what queue to put your map into, just put it into as many as you want or as few as you would like. It does nothing for you except applying the mods and keeping track of what people/queues are done or are in progress.
Just go to the designated modding queue subforum for your map (osu!, taiko, catch, mania) and post it in a few, try to look for more active ones and of course, like above, make sure that your map isnt going to get auto rejected based on preferences and what they are willing to mod. Also, keep in mind that these are real people too, and most likely your age or similar in age, so they've probably got school or other activities that may take them away for some time, so be patient and allow for them to work their magic, just like you worked magic on your beatmap!
If you are getting no mods from the forums and from osumod.com, try going into #modhelp, or even joining some global/mapping discords for your preferred gamemode. More often than not they will have a modding channel where you can post it and as it is discord more people are inclined to look at it and even check their notifications.
Regardless, nothing is unrankable, just need to give it enough time or rework it enough. Some other help is to look at other difficulties of the same range and try and see what they are doing with that and maybe even throw your own sparkle of mapping genius onto what they have.
Also. ALWAYS TEST PLAY! It will catch a lot of things that you may think are okay until you play them.