1. He is outgoing.

Question

2. He is extrovert.
3. He is extroverted.
(Are they all grammatical and the same in meaning?)

4. He is shy.
5. He is reserved.
6. He is introvert.
7. He is introverted.
(Are they all grammatical and the same in meaning?)

Answer 1

2. He is an extrovert.

6. He is an introvert.

All the others are correct. And yes, 1-3 mean about the same thing, and 4-7 mean about the same thing.