Jiren was able to fight Goku and put him in trouble when he was using half Ultra Instinct. Does Jiren also have Ultra Instinct? This is a shot from the preview of the next episode, where Goku using complete Ultra Instinct fight against Jiren. Dont both Goku and Jiren have the same kind of aura? If so, does this mean they both have Ultra Instict?
No. Ultra Instinct a state which allows the body to completely react on its own, in other words, it helps maximise reaction time but in case of Goku, the transformation seems to act as a power multiplier which makes him absurdly strong.
Jiren on the other hand, has a Very good reaction time and an absurd amount of strength. This is what makes him strong enough to take blows from Ultra Instinct Goku and him being able to dodge some of the attacks. We see this during the fight between Jiren and Hit. Even when Hit tried attacking from a different dimension and even during his time-skips, Jiren was still able to immediately react without much effort. This is why he was able to dodge a few attacks from Ultra Instinct Omen Goku. The only fighters who have Ultra Instinct currently would be the Angels and Goku.