गुप्त साम्राज्य का प्रसिद्ध ऐतिहासिक स्रोत 'प्रयाग प्रशस्ति' आमतौर पर किस नाम से भी जाना जाता है?

In Ancient Indian Statecraft, Kautilya's 'Rajamandala' theory primarily deals with:

The First Buddhist Council was held at ______.

Which ancient Indian text contains references indicating that population counts or census-like records were maintained in ancient India?