Shradh as a ritual for ancestors is not part of Jain dharma.

What Jains typically do instead

• Live a virtuous life now: follow ahimsa (non-violence), truth, non-stealing, celibacy, and non-possessiveness to reduce karmic bondage.
• Remember ancestors through positive actions: charity (dāna), helping others, and practicing daily prayers like Samayik and Pratikraman.
• Nurture spiritual growth during important Jain periods: Paryushan, Das Lakshan, and regular meditation and reflection.

Note on tradition

• Both Digambar and Śvetāmbar traditions do not prescribe Shradh or Pitru Paksha as Jain rites. Any ancestor-related practices are informal or personal/customary, not canonical Jain vows. ( jainknowledge.com)

You can read more here:

• Do Jains consider Pitru Paksha inauspicious?
• Do Jains believe in the month of Shradh?