For Rahu related problems and during the dasa or antardasa of Rahu:
1. Worship Bhairava or lord Shiva.
2. Recite the Kalabhairav asthakam.
3. Japa of the rahu beeja mantra: Om bhram bhreem bhroum sah rahave namah, 18000 times in 40 days.
4. Recite the Rahu stotra:
Ardha Kaayam maha veryam chandraditya vimardhanam
Simhika garbha sambhutam tam rahum pranamamyaham.
5. Donate: Udad dal or coconut on Saturday.
6. Fasting on Saturdays.
7. Pooja: Bhairav or Shiva or Chandi pooja.
8. Wear An 8 mukhi Rudraksha.
9. One of the best remedies for rahu is reciting the first chapter of Durga Saptasati.