These are two different Puja, there is no doubt that Kaalsarp dosha is formed due to Rahu and ketu, however the puja and Mantras are different. For Kaalsarp dosha you will recite nag gayatri mantra and for Rahu you will recite the Beej mantra of Rahu.
Some even do the Maha mritunjaya Mantra for Kaalsarp dosha.
Your body is 100crore worth machine.
When planets are badly placed,your body machine becomes defective.
Pujas and other simple remedies will help only in a small way.
You should clean your machine by penance.
Take only salf free food for one day in every three days.
Observe fasting one day in a week.On that day you can eat
only uncooked vegeteables,unlimited.
Feed birds and animals.
Please read the article in google-kumrao99 penance method. firstname.lastname@example.org