There is a fair amount of confusion among the seekers wondering whether there should be no effort as quoted by many teachers of Advaita or as others teach, should effort be made to realize their True Nature or the Truth. The answer to that question can be aptly put as "it depends". Why so? Let us start with who is it that wants the answer. If the one who is seeking the answer is an independent person or entity that wants the answer, then it can be stated that definitely effort is required for one to attain Realization. However, if one has already reached the conclusion that one is not an independent entity or a person but the Universal Consciousness itself, then such a question would not arise in the first place and most likely the answer would be " no effort is required since you already are what you are seeking".
As you can see it depends on your perspective and concepts. As long as you hold on to the concept of being an individual, separate from the rest of the world, in that case effort is certainly required. The effort in not in trying to gain something, but actually in trying to lose this sense of individuality that you have taken for granted and are unwilling or uninterested in losing. The Truth is one and is always unchanging, eternal and omnipresent. It is the false that is shrouding the Truth and hence it is the false that must be removed by whoever wants to discover the Truth. The false, in this case, would be the sense of individuality or ego. Hence, all effort should be focused on the inquiry into the nature of one's self (note the small "s") which is the ego, or the false sense of being an independent individual apart from the consciousness. This individual wants to discover the Truth. The false is nothing but the strong belief in the existence of the ego. So, ask the question, "who am I?" in which the "I" is the ego or the sense of individuality. Dive deep into this sense and find out wherefrom does it arise. Was it there in deep sleep? Investigate!
When one finds out the answer to the existence or non-existence of the ego, then the rest is simple and straightforward. Do you make any effort to be? Answer this question yourself. Did you choose to be born? Did you choose the family into which you claim to be "born" into? Did your parents choose that it should be "you" that they want? Did they have any knowledge of the exact moment of "your" conception? Even if you now consider yourself to be this body, did you make any effort to evolve from the tiny few cells in the womb to the fully formed infant that came out of the womb? Are you making any effort to beat your heart, grow your hair, grow the nails, digest the food, or create the urine by the kidneys? Investigate in this direction and see what exactly are you and what exactly do you DO.
In closing, whether or not any effort is needed in Self Realization depends on who is asking the question, and not on the answer. Hence, the answer given to the seeker depends on the Master or Guru knowing fully well as to who is asking the question and giving the answer accordingly.