Can I use the screenshots from the galleries on other website?
If it's screenshots from the actual movie/TV series, then yes. As long as you're not trying to make profit off of it or claim it as your own.
If it's someone else's work rendered over it, 99% of the time the answer will be no unless you ask permission. Even then, the editor still may say no. If you ARE given permission though, don't try to claim it as your own.
I hope this answers your question.