You should do Pratikraman (pratikaman) at these times:

1. Every day – best practice

- Morning (Raisi / Rai Pratikraman) - Done in early morning, ideally before sunrise. - You reflect on and repent for faults done in the previous night (from yesterday evening till you slept / midnight etc.).

- Evening (Devasi Pratikraman) - Done after sunset, usually in the early night. - You reflect on and repent for faults done in the whole day.

1. If you cannot do it daily

- Pakshik Pratikraman – once every fortnight (twice in a lunar month). - Chaumasi Pratikraman – once in four months. - Samvatsari / Kshamavani Pratikraman – once a year, during: - Paryushan + Samvatsari (mainly Shwetambar tradition) - Das Lakshan and Kshamavani (mainly Digambar tradition)

1. Best principle

- Whenever you feel you have done any sin, mistake, or himsa (violence) by mind, speech, or body, you should do Pratikraman as soon as possible in your heart, and formally at the next proper Pratikraman time.

So, in simple words: Ideal = twice daily (morning + evening). Minimum = at least once a year on Samvatsari / Kshamavani. Better = daily, or at least Pakshik / Chaumasi + yearly.

You can read more in detail here