So two alternatives. If a Kṛṣṇa conscious person could not complete the course, then he gets another chance. Śucīnāṁ śrīmatāṁ gehe yoga-bhraṣṭo sanjāyate. Yoga-bhraṣṭa means one who falls down. But there is no cause of falling down if we are strict. Just like if a student is studying nicely, he will pass his examination. Where is the difficulty there? If he neglects, he may fail. But even if he fails, then he gets the chance of getting a human body. Otherwise there is no guarantee. Kṛṣṇa says, tathā dehāntara-prāptiḥ (BG 2.13). You have to change this body. But what kind of change? That will depend on your work.
You are being educated with the expectation of being situated, posted, in some nice occupation, but that occupation will depend on your work in student life. You may become a high-court judge, you can become a great engineer, you can get so many things, or you could not get anything, such post. That will depend on your work. Similarly, this life is preparation for the next life. So best thing is that you prepare, heart and soul, for going back to home, back to Godhead, Kṛṣṇa consciousness. That is the highest perfection of life. Our students are being taught in that way, highest perfection of life.