I have a little confused about what you ask. I think that you are going to upload already created videos or use the same content in your channel. If you have the same idea, creative commons videos on YouTube are my suggestion for you. Because there is no copyright issue for reuse and it is accepted by YouTube too.So, simply go to YouTube, search your keyword and click filter then click creative Commons. Finally, you will show free videos for reuse. This is the only way I know and if you get to know new in the future let me know. And I like to share my thoughts here.Personally, I feel that you are expecting a great niche. If you have any issues selecting a profitable niche for YouTube, I can help you at this moment. Because I also faced this problem and I fixed this with clear guidance. Let