Short answer: Navratri is a Hindu festival and is not a standard Jain observance. After death, a Jain’s focus is on cleansing karma and seeking moksha, not on Navratri rites.

If you are asking about a Jain practice that resembles a long, disciplined pilgrimage linked to a Tirthankar, there is Navanu Jatra (Navanu Yatra). It is a traditional Jain penance/sadhana connected with Adeshwar Dada (Adinath) at places like Shatrunjaya Palitana. It is not a ritual after death, but a strenuous devotional practice undertaken by some followers to purify the soul and progress toward liberation. Different Jain communities (Digambar and Śvetāmbara) may emphasize slightly different details, but the core idea remains a disciplined penance in honor of the Tirthankar. You can read more here