On the occasion of Brindavana Dwadashi on Tuesday (15.11.2021), it is important for everyone to perform Tulasi Puja and Tulasi Vivaha (with Sri Mahavishnu, in Amalaka, i.e. Nelli chedi). Note that Ekadashi vratam is also on 15.11.2021 and Dwadashi paaranai is on 16.11.2021.
The following PDFs in multiple scripts give the detailed Puja Vidhanam for performing
Puja of Sri Tulasi Devi with Sri Mahavishnu, and Tulasi Vivaha:
[Tamil Diacritics 2-3-4] https://bit.ly/tulasi-puja-tamil
[Tamil Grantha] https://bit.ly/tulasi-puja-tamil-grantha
Jaya Jaya Shankara! Hara Hara Shankara!
Asthika Dharmam, Ky. Bharaneedhara Sastrigal