What happened after the decline of Harappan cities?

After the decline of Harappan cities, around 1900 BCE, many of the people moved to new areas, and smaller settlements emerged in different regions. The decline may have been caused by factors like climate change, shifting river courses, or natural disasters. In the post-Harappan period, the people continued to live in the same areas but adapted to new ways of life. The use of new materials and tools increased, and there was a shift from urban life to rural settlements. This period eventually led to the rise of new cultures in the Indian subcontinent.

This question related to Chapter 6 Social Science Class 6th NCERT.
From the Chapter 6. The Beginnings of Indian Civilisation.
Give answer according to your understanding.