Matsya Purana — Characteristics of Dvāpara and Kali Yugas
प्राच्यान्प्रतीच्यांश्च तथा विन्ध्यपृष्ठापरान्तिकान् तथैव दाक्षिणात्यांश्च द्रविडान्सिंहलैः सह //
prācyānpratīcyāṃśca tathā vindhyapṛṣṭhāparāntikān tathaiva dākṣiṇātyāṃśca draviḍānsiṃhalaiḥ saha //
Likewise (they enumerated) the Easterners and the Westerners, those dwelling along the Vindhya back-slopes and in Aparānta (the western coastal tract), and also the Southerners—the Draviḍas—together with the Siṃhalas (people of Laṅkā/Sri Lanka).
This verse does not describe Pralaya; it belongs to a geographic/ethnographic listing that classifies peoples by direction and major regions (east, west, Vindhya tract, Aparānta, south, Draviḍa, and Siṃhala).
Indirectly, such regional catalogues support the Purāṇic view of orderly governance: a king is expected to know the extent of realms, frontier regions, and peoples (janapadas) for administration, alliances, and protection, even though no explicit duty is stated here.
No direct Vāstu or ritual rule is stated; the significance is contextual—temple/ritual traditions in Purāṇas are often mapped onto sacred geography, and this verse contributes to that broader spatial framework by naming key regions and peoples.