Answer
The first thing that is important in answering this question is to understand what is meant by brahmacharya.
If by brahmacharya you mean remaining celibate throughout your period of study, then yes, it is certainly possible. A student can remain celibate and focus fully on his responsibilities as a student. The purpose of student life is to dedicate one's energy and attention to education, learning, and self-development, without becoming distracted by activities unrelated to one's studies.
Serious study is best accomplished when the mind remains peaceful and undisturbed. Therefore, one should minimize unnecessary association and interaction that may distract the mind from its primary purpose. By maintaining discipline and focusing on one's education, one can successfully practice celibacy during student life.
However, if by brahmacharya you mean following all the traditional rules and regulations described in the Dharma-shastras for the brahmachari ashrama, then that is a different matter.
The classical system of brahmacharya described in the scriptures was practiced in previous ages under very different social and cultural conditions. A young boy would leave home at an early age and reside in a gurukula under the direct care and protection of a spiritual master. The entire environment was designed to train him in discipline, character, knowledge, and spiritual values.
From childhood until approximately twenty-five years of age, the brahmachari would remain fully dedicated to serving the spiritual master, learning from him, making sincere inquiries, and cultivating spiritual and practical knowledge. He would assist the guru in various ways, including collecting alms on behalf of the gurukula. Whatever he collected would first be offered to the spiritual master. Only after the guru had accepted and arranged for the students' needs would the brahmacharis take their meals.
Such a system required a highly qualified spiritual master, a dedicated educational institution, disciplined students, and an entire social structure that supported this way of life.
In the modern age, those circumstances generally do not exist. Society has changed, educational systems have changed, and most people are neither situated in nor trained for that traditional mode of life. Therefore, the full classical model of brahmacharya as described in the Dharma-shastras is not practical for most people today.
What is practical, however, is to follow the essential principle of brahmacharya: self-discipline, control of the senses, purity of conduct, focus on one's duties, and the avoidance of unnecessary distractions. To the extent that one sincerely practices these principles, one can benefit greatly from the spirit of brahmacharya even in modern circumstances.
