Under U.S. law, Section 230 (47 U.S.C. § 230) limits liability for comments solely to the comment maker and not to the video uploader or YouTube. It basically says that there is no duty to moderate except for copyright upon a takedown notice. Normally takedown notices would be directed to YouTube which has a process that handles that, and not to the uploader, even though the uploader would have a limited able to comply if a comment if problematic.
Since YouTube is U.S. based, Section 230 carries a lot of weight in both being law that is relevant to the platform and in setting norms about what is expected of participants in that platform, but it is not binding on other countries. Another country could impose liability on someone who has the ability to delete comments, even though U.S. law would not impose it.
The section of the India IT Act referred to in the question states:
Central Government Act
Section 79 in The Information Technology Act, 2000
95 [ 79 Exemption from liability of intermediary in certain cases. -
(1) Notwithstanding anything contained in any law for the time being
in force but subject to the provisions of sub-sections (2) and (3), an
intermediary shall not be liable for any third party information,
data, or communication link made available or hosted by him.
(2) The provisions of sub-section (1) shall apply if-
(a) the function of the intermediary is limited to providing access to
a communication system over which information made available by third
parties is transmitted or temporarily stored or hosted; or
(b) the intermediary does not-
(i) initiate the transmission, (ii) select the receiver of the
(iii) select or modify the information contained in the transmission;
(c) the intermediary observes due diligence while discharging his
duties under this Act and also observes such other guidelines as the
Central Government may prescribe in this behalf.
(3) The provisions of sub-section (1) shall not apply if-
(a) the intermediary has conspired or abetted or aided or induced,
whether by threats or promise or othorise in the commission of the
(b) upon receiving actual knowledge, or on being notified by the
appropriate Government or its agency that any information, data or
communication link residing in or connected to a computer resource,
controlled by the intermediary is being used to commit the unlawful
act, the intermediary fails to expeditiously remove or disable access
to that material on that resource without vitiating the evidence in
Explanation. -For the purpose of this section, the expression "third party information" means any information dealt with by an intermediary
in his capacity as an intermediary.
Section 79 of the India IT Act appears to be modeled on Section 230 under U.S. law. And, it would appear to be a fair reading that YouTube and not the uploader is the "intermediary" for purposes of Section 79, so the uploader might not have express immunity from liability under Section 79. But it also seems unlikely that the common law in India would impose liability on an uploader for failing to moderate comments that is not imposed upon YouTube which is statutorily absolved of the same liability.
Since the uploader is probably not an intermediary, this also means that liability for failing to respond to a takedown notice under the India IT Act absent of court order, is probably also non-existent.
Any common law action to impose liability (or a statutory action under copyright law) requires a showing of a prima facie case, which involves a showing of a legally recognized duty to act or to refrain from acting. I doubt that the law of India would find a legally recognized duty of a YouTube uploader to delete offending content from a YouTube run comment forum in which the uploader is given limited rights, even though Section 79 does not appear by its own terms to prohibit that liability from being imposed.
For example, I think it is unlikely that a court in India would find that a comment made by a third-party to an uploaded post would constitute "publication" of a defamatory statement by the uploader (or of copyrighted material by an uploader), which is an element of defamation and copyright liability. But I wouldn't be surprised if the case law on point is thin or non-existent as this is a relatively new phenomena and it isn't an intuitively very natural way to apply pre-Internet law to these new circumstances.