Yes it’s true that Rahu afraid of Mars. As some says yes or some says no to this contradictory astrological debate, in this post I would help you to understand the concept behind this mater which would clear your doubts.
Example no – : Since Rahu is a smoke and Mars is fire, similarly if fire is at the high intensity then there will be less smoke, thereby if Mars is strong then it will inhibit to form smoke which is Rahu.
But if your natal chart having the Mars-Rahu conjunction then this conjunction will weaken Mars because only the aspect of Mars on Rahu is considered powerful but conjunction is not because this conjunction is known as Mangal-Rahu Maharaj Dosha.
I would like you to know that Dosha is a conjunction between two opposite energies which gives only problems, because the spark between the rival planets causes serious problems in life.
Summarily if Rahu is aspecting to Mars then Mars would be weak but contrary to this, if Mars is aspecting to Rahu then scene will change. On the other hand one another factor which controls Rahu, you would be surprised that, Shani also controls Rahu, because Rahu is just like an agent of Shani, whatever Shani wants to do Rahu perform at is.
I hope this answer would clear your doubts related to Rahu.