Is Sasuke still a Genin?
Just like Naruto, Sasuke Uchiha never got another shot at the Chunin Exams and thus never progressed past the rank. Even though he's stronger than any of the Kage, excluding Naruto,
Sasuke is still a Genin. His skill alone puts him way above the rank of a Jonin.
Did Sasuke become a jonin?
He
became Hokage as a genin,” the artist explained. Kishimoto even went on to say Sasuke never upped his ninja rank after he gave up his rogue status. “Sasuke is not a jounin or chuunin either, but rather, since he left the village, he is a nukenin.