Which are the nine gates being referred here? Are these ears, nose, mouth, eyes etc?
Yes the Nine gates referred here ae our bodily organs like ear , nose , mouth etc. within Pancala kingdom (5 senses ).
It's said that a jiva accepts a material body by virtue of his own desires. Accepting two hands, two legs, and so on, the living entity fully enjoys the modes of material nature.
These physical gates are in very detail are described in this chapter. I am herewith quoting some of the verses. We can read about these Nine gates in details in this chapter- SB 4.29:Talks Between Nārada and King Prācīnabarhi of Shreemad Bhagvatam.
यदा जिघृक्षन्पुरुषः कार्त्स्न्येन प्रकृतेर्गुणान् ।
नवद्वारं द्विहस्ताङ्घ्रि तत्रामनुत साध्विति ॥SB 4.29.4॥
yadā jighṛkṣan puruṣaḥ kārtsnyena prakṛter guṇān
nava-dvāraḿ dvi-hastāńghri tatrāmanuta sādhv iti
When the living entity wants to enjoy the modes of material nature in
their totality, he prefers, out of many bodily forms, to accept that
body which has nine gates, two hands and two legs. Thus he prefers
to become a human being or a demigod.SB 4.29.4
बृहद्बलं मनो विद्यादुभयेन्द्रियनायकम् ।
पञ्चालाः पञ्च विषया
यन्मध्ये नवखं पुरम् ॥SB 4.29.7॥
bṛhad-balaḿ mano vidyād ubhayendriya-nāyakam
pañcālāḥ pañca
viṣayā yan-madhye nava-khaḿ puram
The eleventh attendant, who is the commander of the others, is known
as the mind. He is the leader of the senses both in the acquisition of
knowledge and in the performance of work. The Pancala kingdom is
that atmosphere in which the five sense objects are enjoyed. Within
that Pancala kingdom is the city of the body, which has nine
gates.SB 4.29.7
These nine gates are described in this verse by Sage Narada in the same chapter .
अक्षिणी नासिके कर्णौ मुखं शिश्नगुदाविति ।
द्वे द्वे द्वारौ
बहिर्याति यस्तदिन्द्रियसंयुतः ॥8॥
akṣiṇī nāsike karṇau mukhaṁ śiśna-gudāv iti
dve dve dvārau bahir
yāti yas tad-indriya-saṁyutaḥ
The eyes, nostrils and ears are pairs of gates situated in one place.
The mouth, genitals and rectum are also different gates. Being placed
into a body having these nine gates, the living entity acts externally
in the material world and enjoys sense objects like form and
taste.SB 4.29.8
Purport: : Not being aware of his spiritual position, the living entity, directed by the mind, goes out through the nine gates to enjoy material objects. Because of long association with material objects, he forgets his real, spiritual activities and is thus misled. The entire world is going on being misled by so-called leaders like scientists and philosophers, who have no knowledge of the spirit soul. Thus the conditioned soul becomes more and more entangled.
Shree Krisha is talking about these Nine gates in the chapter 5 - verse 13 of Shreemad Bhagvat Gita.
सर्वकर्माणि मनसा संन्यस्यास्ते सुखं वशी।
नवद्वारे पुरे देही नैव कुर्वन्न कारयन्।।5.13।।
sarva-karmāṇi manasā sannyasyāste sukhaṁ vaśī
nava-dvāre pure dehī naiva kurvan na kārayan
When the embodied living being controls his nature and mentally
renounces all actions, he resides happily in the city of nine
gates[the material body], neither working nor causing work to be
done.
And here is English Translation of Shree Ramanuja's Sanskrit Commentary By Swami Adidevananda.
5.13 The embodied self who is self-controlled, renounces all actions to the city of nine gates, i.e., the body with its sensory and motor
functions which are nine in number. He discriminates that all actions
are due to conjunction of the self with the body which is rooted in
previous Karmas, and is not by Its own nature. [It means that the self
merely rests in the body, without any identification with bodily
activities.] Sri Krsna now teaches the natural condition of the self
as It is: