Did Nāgārjuna describe features of the Fourier transform? The Fourier transform describes how to transform between cyclic and non cyclic. Did Nāgārjuna describe this already several centuries before Fourier as described in Mūlamadhyamakakārikā 25:19-20?
A full translation to western terms is

25:19–20
न संसारस्य निर्वाणात् किं चिद् अस्ति विशेषणं
na saṁsārasya nirvāṇāt kiṁ cid asti viśeṣaṇaṁ
There is nothing whatsoever of the cyclic distinguishing (it) from the non cyclic.
ननिर्वाणस्य संसारात् किं चिद् अस्ति विशेषणं। १९
na nirvāṇasya saṁsārāt kiṁ cid asti viśeṣaṇaṁ| 19
There is nothing whatsoever of the non cyclic distinguishing it from the cyclic.
निर्वाणस्य च या कोटिः।कोटिः। संसरणस्य च
nirvāṇasya ca yā koṭiḥ koṭiḥ saṁsaraṇasya ca
(That?) is the limit which is the limit of the non cyclic and the limit of the cyclic;
न तयोर् अन्तरं किंचित् सुसूक्ष्मम् अपि विद्यते। २०
na tayor antaraṁ kiñcit susūkśmam api vidyate| 20
Even a very subtle interval is not found of (between) them.
Nāgārjuna was not a mathematician; he was an eminent buddhist philosopher. That is certainly enough, don't you think?
There is an interesting parallel here, perhaps — maybe even a useful analogy, though one that would only be meaningful to people who understand Fourier transforms — but that's all. The claim inside the question asked is mere puffery (great word, puffery), but if we puff Nāgārjuna up with undeserved praise we deflate that which he actually deserves praise for.
A thousand people can all look at the same thing and describe it in a thousand different ways. Laozi described it centuries before Nāgārjuna, but we wouldn't give Laozi credit for Nāgārjuna's vision, and we shouldn't give Nāgārjuna credit for Fourier's vision.