What is the function of the 'Chatra' on top of a stupa?

It is a triple umbrella symbolizing high rank and providing symbolic protection/veneration to the relics within.

Stupa Architecture

UPSC Archival Analysis

The Sanchi Stupa was originally constructed by the Mauryan Emperor Ashoka in the 3rd century BCE as a brick structure to house Buddhist relics.

Exam Year

1991

Evidence Source

ID: ART_ARC_1991_107 Ref: Asoka and the Decline of the Mauryas by Romila Thapar