Were there companions of the Messenger of Allah, may Allah bless him and grant him peace, from among the jinn? Are they still in existence? And is there marriage between humans and jinn, and what is its ruling?

It is authentically reported in Sahih Muslim that the Prophet (peace be upon him) went out to the jinn and recited the Qur'an to them, and they believed in him. As for marriage between humans and jinn, it is impermissible and invalid.