"What do you think of other spiritual teachers such as Ramana Maharshi or Nisargadatta Maharaj? Can they help me to know enlightenment?"
I am not at all sure about Ramana or Maharaj. It is interesting to read what others have said, but the only thing one can be sure of is the way the organism is functioning from moment to moment.
It is very interesting to see, because if one has the idea liberation can be known, there is also the desire to fix it into something that can be kept. Not only can the known be manipulated and shaped into a form pleasing to the self, it can also be maintained and held onto. But is any of that liberation? Can liberation be maintained, held onto, or kept like a prize?
Part of the problem might be the sheer amount of writing on liberation; liberation is like this, or like that. The problem arises when one reads it. They want to get it, so they follow the words carefully, memorizing certain passages, trying to get the effect of the words. This is all a part of the same game of identity. The self needs something in order to feel complete and whole.
The idea of enlightenment is put on the pedestal, perhaps the highest pedestal, and sought after like any other desire. I want to be respected, I want to be loved, I want to be strong, I want power, I want to have sex, I want to have your approval; this is no different from, I want to be enlightened. Some might fool themselves into believing it is higher, but it is the same mechanism doing the searching. This movement of self, believing it is incomplete, cannot see that it is already whole.
Some have said (and perhaps Takuin has also said), liberation is beyond thought. It may be more fitting to say, liberation is beyond identity. It has nothing to do with what we think; nothing to do with what we hope it will be. The movement of the seeker seeking the prize is not a complete movement, as the seeker itself is built from fragmentation. So how can the seeking thought, I-thought, or whatever, hope to be full and complete when everything it does springs from a fragmented center?
This is the unfortunate nature of the search. One realizes in the end, so much energy is wasted in the search. While the complete being, and the wholeness sought, is never absent.
The searcher can be the cruelest of tormentors.