Why do we say Ram Ram as greeting?
As per Skanda Purana" उनके स्वरूप में रमण करता है , इसलिये उनको ' राम ' कहते हैं ।"
The Ramayana was written by sage Valmiki, but prior to being a sage he was a thief in his earlier life,
One day Sage Narad muni told Valmiki to chant Mara Mara, when he chanted continuously it was pronounced as Rama Rama to show him the path of life and achieves enlightenment.
Once he understood the meaning of Rama, he stopped looting and killing people, and got relieved of his sins. He then continued to walk on the path of truth, honesty, and kindness and wrote the Hindu epic –Ramayana.
A perfect example showing the power of word "Ram" which prevents us from committing the sins and relieves us from the negative effects of the sins. It protects us from the negative energies present in the universe,
If we look into Hindi alphabets, R (र) is the 27th letter and Aa (ा) is the 2nd vowel and M is the 25th letter.
The total of Ram (राम) is; 27+2+25 :54.
Twice (राम, राम) would mean 54+54 : 108.
Every mantra we chant (Jap) is done for minimum 108 times, hope you all know what’s the importance of 108 number in Sanatan Dharma.
When we say Ram Ram (राम, राम) it completes one Mala /108 times, so we take Lord Ram’s name twice only when we meet any one.
The number 108 has been designed on the basis of stars (नक्षत्र), the ancient sages discovered 27 different stars, and each start has four different phases (चरण) , finally 27 x 4 is 108 and thus 108 and is considered as sacred number, so doing one circle of 108 beads is equal to the one circle of universe,