It is not clearly described. People of all castes can become Vaisnavas, but according to sastra, only those who are twice born can accept sannyasa. In Srimad-Bhagavatam (7.11.35), Narada describes the separate characteristics of each of the different varnas, and then concludes with this statement:
“A person should be considered to belong to the varna whose characteristics he possesses, even if he has appeared in a different caste.”
The practice of offering sannyasa to men who, although born of other castes, possess the symptoms of brahmanas, is occurring on the basis of this verdict of the sastras. If a man born of a different caste truly possesses the symptoms of a brahmana and is given sannyasa, then it must be avowed that this system is approved by sastra.
This verdict of the sastras supports the practice of offering sannyasa to men who possess brahminical symptoms, even though they are born of other castes, but it only applies to paramarthika, or absolute, affairs, and not to vyavaharika, or relative, affairs.
Today I have been blessed. Of all the instructions that have flowed from the mouth of the most revered Babaji Mahasaya, these are the points I have been able to assimilate. The jiva is an eternal servant of Krishna, but he forgets this and takes on a material body. Influenced by the qualities of material nature, he derives happiness and distress from material objects. For the privilege of enjoying the fruits of his material activities, he must wear a garland of birth, old age, and death.
The jiva sometimes takes birth in a high position and sometimes in a low position, and he is led into innumerable circumstances by his repeated change of identity. Hunger and thirst spur him to action in a body that may perish at any instant. He is bereft of the necessities of this world, and is cast into unlimited varieties of suffering. Many diseases and ailments appear which torment his body. In his home, he quarrels with his wife and children, and sometimes he goes to the extent of committing suicide. His greed to accumulate wealth drives him to commit many sins. He is punished by the government, insulted by others, and thus he suffers untold bodily afflictions.
He is constantly aggrieved by separation from family members, loss of wealth, theft by robbers, and countless other causes of suffering. When a person becomes old, his relatives do not take care of him, and this causes him great distress. His withered body is ravaged by mucus, rheumatism and a barrage of other pains, and is simply a source of misery. After death, he enters another womb and suffers intolerable pain. Yet despite all this, as long as the body remains, his discrimination is overpowered by lust, anger, greed, illusion, pride, and envy. This is samsara.
I now understand the meaning of the word samsara. I repeatedly offer dandavat-pranama to Babaji Mahasaya. The Vaisnavas are gurus for the entire world. Today, by the mercy of the Vaisnavas, I have acquired real knowledge of this material world.
When the Vaisnavas present had heard Ananta dasa Babaji Mahasaya’s profound instructions, they all loudly exclaimed, “Sadhu! Sadhu!” By this time, many Vaisnavas had assembled there, and they began to sing a bhajana that Lahiri Mahasaya had composed.
The jiva who has fallen into this dreadful material existence finds no end to his distress, but his troubles come to an end when he is graced by the association of sadhus and then takes to the worship of Sri Hari.
The raging fire of sensual desires scorches his heart, and when he tries to satisfy those desires, the fire simply flares up with greater intensity. However, relinquishing offenses and chanting sri-Krishna-nama acts like a cooling shower of rain, which extinguishes this blazing fire.
Tridanda-sannyasa is the real, perpetual sannyasa, and it is applicable at all times. Sometimes tridanda-sannyasa externally appears in the form of ekadanda-sannyasa. Ekadanda-sannyasis of this type, who are actually great souls, accept the eternality of tridandasannyasa that symbolizes the three features of sevya (the object of service), sevaka (the servitor), and seva (service). Such people consider the ekadanda-sannyasa propagated by Sankara to be completely unauthorized and not supported by sastra. It is therefore proven, even because of the Brahma-vaivarta Purana sloka cited by smarta acaryas, that it is logical for sadhakas who are pursuing the nivrtti-marga to accept sannyasa.