Rama mantra is the Thaaraka mantra

Mantra’ means energy and ‘Thaaraka’ means ‘a thing that takes you across’. Rama mantra takes you across the sea of worldly life and helps you cross it to reach the other world.

 

Narayana and Shiva are our main deities.  Moola mantra for Narayana is Om Namo Narayana. Moola mantra for Shiva is Om Nama Shivaya

In Narayana Moola Mantra, “Om Namo Narayana," the life of the mantra lies in the letter "ra.  If the letter "ra" is removed, the moola mantra becomes inauspicious. Om Namo Narayana becomes Om Namo Nayana

In the Shiva moola mantra, “Om Nama Shivaya”, the life of this mantra lies in the letter "ma". If the letter "ma" is removed, the moola mantra becomes inauspicious.Om Nama Shivaya  becomes Om Na Shivaya

The life packed these 2 letters of the moola mantras combine to form the Thaaraka Mantra – “RAMA” (Ra+Ma)"

‘Saint Tyagaraja  explains this in his Kriti - Evarani Nirnayinchiri

Siva mantramunaku ³ma jIvamu
mAdhava mantramunaku rA jIvamu(y)I
vivaramu telisina ghanulaku mrokkeda
vitaraNa guNa ⁴tyAgarAja vinuta 

The meaning of the above is as follows

“For the Siva mantra (OM namaSSivAya), ‘ma’ is the soul; for the vishNu mantra (OM namO nArAyanAya), ‘rA’ is the soul; I salute the great personages who understand this detail”

That’s why Rama Nama is called Thaaraka mantra.

Let's Think of the glory of Rama, involve in his Japa and seek liberation from our sins