user11541: I have found a text which states that 

nibbāna is a description meaning not-self.

The meaning of the text is clear. Nibbana is nothing but not-self.
Moreover I have also found a sutta(SN22.45) which says that after understanding and realizing not-self the person attains Nirvana.

At Savatthi. “Bhikkhus, form is impermanent. What is impermanent is
  suffering. What is suffering is nonself. What is nonself should be
  seen as it really is with correct wisdom thus: ‘This is not mine, this
  I am not, this is not my self.’ When one sees this thus as it really
  is with correct wisdom, the mind becomes dispassionate and is
  liberated from the taints by nonclinging

.
.
.

“By being liberated, it is steady; by being steady, it is content; by
  being content, he is not agitated. Being unagitated, he personally
  attains Nibbāna.

My question is :Does Nibbana mean not self?

user471: Anatta or not-self is a characteristic of all phenomena (including Nibbana), regardless of whether they are conditioned or unconditioned, compounded or uncompounded, permanent or impermanent.
Nibbana is the phenomena which is the end of suffering. It's unconditioned, uncompounded and not impermanent. It's also not-self.
Samsara and dukkha (suffering) are also not-self.
Even a stream winner or sotapanna would have overcome the self-view but would not have attained Nibbana yet. In order for the stream winner to reach Nibbana, he needs to overcome the remainder of the ten fetters.

user111: Everything is not-self including Nibbana. But Nibbana is much more than that. It is the end of suffering.

user13375: Much like Sankha and Ruben2020 have said, I think it is imperative to understand that selflessness is an apt description of all persons and phenomena, including nirvana. That is, there is nothing which isn't selfless. Another way of saying this is that all things lack inherent existence; including nirvana. There is nothing neither existent nor non-existent that cannot be described as utterly lacking a self.
But nirvana is not a person so how can it be said to be selfless? Also, it is not an impermanent phenomena so how can it be said to be selfless? 
One part of the confusion here is that it is usually thought that the Pali Canon is only part of the First Turning of the Wheel of Dharma. However, I don't think this is strictly true. The Second Turning of the Wheel of Dharma can be found in the Pali Canon. In Sutras like this and for instance the Kaccayanagotta Sutta we see the Buddha giving teachings that to my mind are very clearly part of the Second Turning. These teachings are elaborated on by the Buddha in strictly Mayahana Sutras and by the Virtuous Teachers such as Nagarjuna. Nagarjuna's Fundamental Treatise of the Middle Way devotes an entire chapter to nirvana and how it is selfless. So how do the Second Turning Virtuous Teachers say that nirvana is selfless?
Nirvana is not a person and yet it utterly lacks any inherent existence. This is how it is said to be selfless. Nirvana is not an impermanent phenomena and yet it utterly lacks any inherent existence. This is how it is said to be selfless. 
Thus, the correct understanding of the selflessness of Nirvana cannot be arrived at without understanding the subtler meanings of selflessness. Understanding selflessness through things not existing permanently, unitarily and independently is the coarsest understanding and this is not sufficient for understanding the selflessness of Nirvana.
Now, does that mean being selfless is a completely sufficient description of nirvana? No. More needs to be said. Nevertheless, nirvana is indeed selfless.
Moreover, understanding the selflessness of all things is essential to gaining our liberation from cyclic existence. Directly realizing the emptiness of all existent and non-existent things and regarding all this as a morass of utterly unreal concepts and appearances is how we arrive at the doorstep of nirvana. I hope this helps.
Finally, I'll note that nirvana comes in two types: with residuals and without. According to my tradition Nirvana without residuals is only attained by fully enlightened Buddhas or Arya beings while in meditative equipoise directly perceiving emptiness.

11541: <p>I have found a <a href="https://suttacentral.net/pli-tv-pvr3/en/horner-brahmali" rel="nofollow noreferrer">text</a> which states that </p>

<blockquote>
  <p>nibbāna is a description meaning not-self.</p>
</blockquote>

<p>The meaning of the text is clear. Nibbana is nothing but not-self.
Moreover I have also found a <a href="https://suttacentral.net/sn22.45/en/bodhi" rel="nofollow noreferrer">sutta(SN22.45)</a> which says that after understanding and realizing not-self the person attains Nirvana.</p>

<blockquote>
  <p>At Savatthi. “Bhikkhus, form is impermanent. What is impermanent is
  suffering. What is suffering is nonself. What is nonself should be
  seen as it really is with correct wisdom thus: ‘This is not mine, this
  I am not, this is not my self.’ When one sees this thus as it really
  is with correct wisdom, the mind becomes dispassionate and is
  liberated from the taints by nonclinging</p>
</blockquote>

<p>.
.
.</p>

<blockquote>
  <p>“By being liberated, it is steady; by being steady, it is content; by
  being content, he is not agitated. Being unagitated, he personally
  attains Nibbāna.</p>
</blockquote>

<p>My question is :Does Nibbana mean not self?</p>
 471: <p>Anatta or not-self is a characteristic of all phenomena (including Nibbana), regardless of whether they are conditioned or unconditioned, compounded or uncompounded, permanent or impermanent.</p>

<p>Nibbana is the phenomena which is the end of suffering. It's unconditioned, uncompounded and not impermanent. It's also not-self.</p>

<p>Samsara and dukkha (suffering) are also not-self.</p>

<p>Even a stream winner or sotapanna would have overcome the self-view but would not have attained Nibbana yet. In order for the stream winner to reach Nibbana, he needs to overcome the remainder of the ten fetters.</p>
 111: <p>Everything is not-self including Nibbana. But Nibbana is much more than that. It is the end of suffering.</p>
 13375: <p>Much like Sankha and Ruben2020 have said, I think it is imperative to understand that selflessness is an apt description of all persons and phenomena, including nirvana. That is, there is nothing which isn't selfless. Another way of saying this is that all things lack inherent existence; including nirvana. There is nothing neither existent nor non-existent that cannot be described as utterly lacking a self.</p>

<p><strong>But nirvana is not a person so how can it be said to be selfless? Also, it is not an impermanent phenomena so how can it be said to be selfless?</strong> </p>

<p>One part of the confusion here is that it is usually thought that the Pali Canon is only part of the First Turning of the Wheel of Dharma. However, I don't think this is strictly true. The Second Turning of the Wheel of Dharma can be found in the Pali Canon. In Sutras like this and for instance the <a href="https://www.accesstoinsight.org/tipitaka/sn/sn12/sn12.015.than.html" rel="nofollow noreferrer">Kaccayanagotta Sutta</a> we see the Buddha giving teachings that to my mind are very clearly part of the Second Turning. These teachings are elaborated on by the Buddha in strictly Mayahana Sutras and by the Virtuous Teachers such as Nagarjuna. Nagarjuna's <em>Fundamental Treatise of the Middle Way</em> devotes an entire chapter to nirvana and how it is selfless. So how do the Second Turning Virtuous Teachers say that nirvana is selfless?</p>

<p><strong>Nirvana is not a person and yet it utterly lacks any inherent existence. This is how it is said to be selfless. Nirvana is not an impermanent phenomena and yet it utterly lacks any inherent existence. This is how it is said to be selfless.</strong> </p>

<p>Thus, the correct understanding of the selflessness of Nirvana cannot be arrived at without understanding the subtler meanings of selflessness. Understanding selflessness through things not existing permanently, unitarily and independently is the coarsest understanding and this is not sufficient for understanding the selflessness of Nirvana.</p>

<p>Now, does that mean being selfless is a completely sufficient description of nirvana? No. More needs to be said. Nevertheless, nirvana is indeed selfless.</p>

<p>Moreover, understanding the selflessness of all things is essential to gaining our liberation from cyclic existence. Directly realizing the emptiness of all existent and non-existent things and regarding all this as a morass of utterly unreal concepts and appearances is how we arrive at the doorstep of nirvana. I hope this helps.</p>

<p>Finally, I'll note that nirvana comes in two types: with residuals and without. According to my tradition Nirvana without residuals is only attained by fully enlightened Buddhas or Arya beings while in meditative equipoise directly perceiving emptiness.</p>
