First of all we should know that Transcendental Meditation is only a practice of concentration. Real meditation is when you become one with the basic force, the consciousness that is working in three levels in our system. One is ‘Material Consciousness’ that is of the outside world cognized through the five senses.
The next is collective consciousness which we call ‘Life-force’, where all the imprints are stored up. When we fix the mind on the life-force we are coming to the collective consciousness. From there, we go to the root, we understand ourselves and that is the third stage which is the stage of ‘Total Consciousness’. Total Consciousness is the ‘Super Mind’, collective consciousness is the ‘Life-Force’ and material consciousness is when the mind is working through the five senses.
Transcendental meditation does not help much to withdraw the mind from its outside activities. The same TM has all along been practiced in India and various places under the title ‘Nama Japa’ / ‘Name Chanting’. This involves chanting repeatedly with stress on the meaning or the ‘Bhavam’ of the words uttered. While name chanting includes the meaning, TM avoids the meaning and goes on with the rhythmic sound. When you go with the sound you eventually become still. This helps to bring the blood pressure (hypertension) down. By taking the mind to a state nearer to the coma state, you are getting away from the tension. But when you go further, along the same line, you lose awareness and there you come to a stop.
Kundalini Yoga is something more than this, it takes you to the relevant region of yourself and all through the process you will retain your awareness. Thus Kundalini Yoga gives you all the benefits of TM and in addition it takes you to perfection. Those who are satisfied with TM could remain there. But if you do not derive complete satisfaction from TM and feel that you have to get something more, then you should take up Kundalini Yoga. After learning and practicing Kundalini Yoga you can still practice TM for your satisfaction for some more time. Say once or twice a week or even daily once or twice. Let me make it clear that TM and SKY will not conflict with each other because both are taking you to the inner side of your own self. Actually if you practice both TM and SKY, in due course you would come to realize that TM is no longer necessary for you. The reason is that SKY takes you beyond the transcendental State.