Mahayana is a technology in Age of Empires II: Definitive Edition - Dynasties of India that is unique to the Bengalis and can be researched at the Castle once the Imperial Age is reached. Once researched, it reduces the population space taken by Villagers by 10%.
This technology allows more Villagers to exist while taking up less space. Villagers will count as 0.9 of a unit instead of 1. For example, this means that 10 Villagers would only equal 9 population wise, or that 20 would equal 18, or that 30 would equal 27, and so on. This paves the way for more Villagers to exist for slightly less population space in the late game, adding a larger boom to an already greatly enlarged economy.
Mahayana is a term for a broad group of Buddhist traditions, texts, philosophies, and practices, which developed in India (c. 1st century BCE onwards). This movement continued into the Pala era (8th century–12th century CE), who were followers and patrons of Mahayana and Tantric schools of Buddhism, during which it grew to dominate Indian Buddhism.
The Palas established the Vikramashila monastery and the Somapura Mahavihara, ordered construction and repairs of several sacred structures at Saranath, Nalanda and Bodh Gaya. Taranatha also credits them with establishing 50 religious institutions and patronising Buddhist authors.