In Jain Dharma, there is no special “Rahu jaap / mantra” given in the scriptures.

Rahu, Ketu, Navgraha etc. come from Hindu / Indian astrology. In Jainism:

• Our sukh–dukh are mainly due to our own karma, not because a planet is pleased or angry.
• So, the remedy (upay) is always:

– right faith (सम्यक् दर्शन) – right conduct (सम्यक् चारित्र) – and shuddh bhavna, not ग्रह‑शांति.

If you are worried about “Rahu mahadasha / dosh” and want to do jaap in a Jain way, the safest and best is:

1. Navkar (Namokar) Mantra Jaap

Daily, with shraddha, e.g.:

> णमो अरिहंताणं। > णमो सिद्धाणं। > णमो आयरियाणं। > णमो उवज्झायाणं। > णमो लोए सव्वसाहूणं। > एसो पंच णमोकारो, > सव्व पावप्पणासणो। > मंगलाणं च सव्वेसिं, > पडमं हवई मंगलं॥

• This is for karmic shuddhi and protection from all negative influences, not only Rahu.
• You can do 11, 21, 108 or any fixed number daily, with pure heart and without लालच (“Rahu ठीक हो जाये बस उसी लिए करूँ”) – just for atma‑shuddhi.

You can read more about Navkar Mantra and its benefits here

2. Other helpful Jain practices

If mind is disturbed due to grah / dasha fear:

• Samayik – sit quietly, do Navkar jaap and pratikraman of krodh, maan, maya, lobh.
• Swadhyay – listen to pravachan or read simple Jain granth; it changes the drashti from planets to karma and atma.

Summary in simple words: Jain Dharma does not give a separate Rahu mantra. For any kind of grah‑dosh fear, do Navkar Mantra, samayik and pratikraman with true faith. That is the real and permanent shanti.