The following excerpt was taken from “The Summits of God-Life: Samadhi and Siddhi” by Sri Chinmoy.
There are some Masters who, after having their major realisation, are asked by the Supreme, “What is your will? What do you want to do?” If the Master says, “I want to work for so many people, I want to do this much work,”then the Supreme says,”All right, granted, with My Blessings.” Then there are some who do not make any hard and fast rule as to how far they want to go. They say, “I will try my best up to the end. I need Your Blessings. I need Your Grace. I will try to manifest as much as possible. I set no limits.”
With some Masters, there is a limit to the number of students they want. With others, there is no end to their aspiration to serve. They remain an open channel and tell the Supreme that they will try their best to fulfil Him and manifest Him until the end of their lives. And not only that, but after leaving the body also, they promise to try to continue His work through their students. So it depends on the individual Master and how much spiritual responsibility he wants to accept.
Regarding the number of students a Master may have, this depends on what kind of people he accepts. If he is very selective and wants only souls that are fully dedicated, intensely aspiring and absolutely destined for the spiritual life, then he will accept only a handful. Sri Ramakrishna, for example, wanted only a limited number of students. He was very particular about his students. But some Yogis say, “Anyone who wants to learn anything about the spiritual life is welcome to my community.” Again, some spiritual Masters say, “Let everyone progress according to his own standard.” So they accept thousands of students.
True spiritual Masters will only accept students who are meant for them. If I know that somebody will make faster progress through some other Master, then occultly and spiritually I will make that person feel in a few months” time that he is not meant for me. What matters is not the number of students a Master has, but whether he takes them to the Goal. If I am realised and somebody else is realised, we are like two brothers with one common Father. Our goal is to take our younger brothers and sisters, humanity, to the Father. The game will be complete only when all people are taken to God. If two Masters are real brothers from the same Father, then how can one Master be unhappy or displeased if somebody goes to the Supreme through the other Master? In the spiritual life we always go together. It is not who has done it, but whether the thing is done. Who has done it is only name and form, which will be obliterated in history. What matters is that evolution has taken place on earth.