What is in adult Niche and are there levels?

Is there a place to see what is considered in each Niche and the degree of it?

If there is a place that ranks niches or labels them, I would like to know.

Asking this question per how I pick sites to redirect to one of my site and the backlinks they have. Already avoiding the sites with too many backlinks like 1M or a bunch of comment forum spamming or straight porn. My site is adult but no where near this degree and wondering what tightrope I can walk. I find sites with with tons of high traffic 50+ DA traffic at times per being persistent and stubborn at times. I don't care about the domain really and just want the backlinks to transfer. The domain and bad links can just add to my 0-10 list.