According to the NEET eligibility criteria:

Eligibility Criteria

- A candidate who has failed in Class 12th examination but has cleared it as a private candidate is eligible to appear for NEET.

- However, the candidate must have passed Class 12th or equivalent examination with Physics, Chemistry, Biology/Biotechnology, and English as core subjects.

Conditions

- The candidate must have passed the Class 12th examination or equivalent with the required subjects (Physics, Chemistry, Biology/Biotechnology, and English) in the first attempt.

- If the candidate has passed the Class 12th examination or equivalent as a private candidate, they must have passed the examination with the required subjects in the first attempt.

Important Note

- It's essential to check the NEET eligibility criteria and the specific requirements of the medical colleges you're applying to, as they may have additional eligibility criteria.

In summary, a student who failed in Class 12th examination but cleared it as a private candidate is eligible to appear for NEET, provided they meet the required eligibility criteria.