How can you do SEO for a video?

Of course you can. Youtube SEO is now trending topic in the SEO industry, but the question is just too broad.

Generally speaking, you need to have good content (suprisingly, right?) so the engagement is high. Good title, description, tags, categories, cc, ... everything does matter to some extent.

But it's mostly about the size of your channel, number of subscribers, history of your videos (views)... It takes a lot of time and effort to get your audience on Youtube. At least, I guess your question is related to Youtube videos.

Thank you for the answer @ms I got it the point and will try it.

Do YouTube keyword research. Know your audience. Optimize your video title. Optimize tour video description. Feature a good video thumbnail. Add appropriate tags to your video. Promote and get more views for your videos.