Yes, an FIR can be filed by the accused but the admissibility of such an FIR in court as a confession is a tangled issue, completely depending on the set of circumstances of the case.

Admissibility as a Confession:

Generally, an FIR filed by an accused is not admissible in the court as a confession. This is due to the following reasons:

1. Voluntariness: A confession should be voluntary and shall be made free from duress or any sort of inducement to be taking as admissible. An FIR filed by an accused does not fall under this category especially at times of coercion or pressure.
2. Warning: Any confession that may have taken place that was recorded would have a proper warning administered before taking such confession due to the ill effects of false confession. An FIR filed by an accused may not have undergone this stage.
3. Self-Incrimination: Thus, the right of every incriminated person not to be self-incriminated is restricted by the filing of an FIR. However, it should be ensured that voluntary statements are not induced or coerced to hold up before this court.

Meaning, an FIR can be filed, but predominantly it will be without evidentiary value. The court would have to look at what circumstances were there under which the FIR was filed, the voluntary nature of the statements, and whether or not procedural safeguards were followed.