Here are some possible corrections and their meanings:
1. Je n'étudie pas. (I am not studying.) This is the most direct and common way to express that you are not studying.
2. Je ne fais pas d'études. (I am not studying/I don't study.) This emphasizes that you are not currently pursuing any education.
3. Je ne fais pas mon étude. (I am not doing my study.) This implies you have a specific study assigned and are not currently working on it.
4. Je ne fais pas d'études à l'université. (I am not studying at the university.) This clarifies that you are not enrolled in university.
5. Je ne fais pas attention en cours. (I am not paying attention in class.) This implies you are not focused on your studies during class time.
To understand the correct meaning, you need more context. Which of these options best fits the situation you are referring to?