Acharyan with his endless mercy performs this third Samskaram known as Nama Samskaram. He Acharyan adds DASA at the end of their names, to signify that he is now the Dasa or servant of Lord Vishnu & Bhagvad Ramanuja through the Acharyan. This is where a person he/she who has other than vishnu names are realloted with Lord Vishnu names.

As said by Bhagath Ramanujacharya "Total Unconditional Surrender to the Lotus feet of Lord Vishnu" is the only way the ordinary jeevathamas like us can attain Mukthi. Sri Vaishnavam was their thousands and thousands of years before Bhagvat Ramanujacharya was born, but it was Ramanujacharya who actually propagated it through a channel where in people from all walks of life can enjoy the benefits of worshiping Lord Vishnu. So it is now certain that he is the leader who can lead us out of the misery of Life and Death, who can show the proper way to lead a devotional meaningful life. It is his Siddhantha we have to follow and a total surrender to his holy feet. We even after undergoing the Pancha Samskaram are not eligible enough to worship the Supreme Lord. We have to go through a Spiritual Master who is first our Acharyan and Bhagvath Ramanujacharya. But Bhagvath Ramanujacharya is the Acharyan of all the Acharya's the Srivaishnavam has ever seen. So we totally surrender ourselves to Bhagvath Ramanujacharya.

We add our names in the following manner:
A person by name Vasudeva who has undergone Samashrayanam is now 
Adeyen Vasudeva Ramanuja Dasan

Adeyen – I am the dust at the Lotus feet of my Acharyan
Vasudeva – Previous name he had
Ramanuja Dasan – I am the eternal Servant of Bhagvath Ramanujacharya

If it is the case of a female who has undergone the Samashrayanam she is called as Ramanuja Dasi.

5 Yaga Samskaram
3 Nama Samskara
1 Thapa Samskara
4 Manthra Samskaram