गुप्त काल में जारी की गई स्वर्ण मुद्राओं को मुख्य रूप से क्या कहा जाता था?

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?