भारतीय उपमहाद्वीप की चित्रित धूसर मृदभांड (Painted Grey Ware - PGW) संस्कृति मुख्य रूप से किस ऐतिहासिक काल से संबंधित 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?