After the fall of the mauryans, what new empire emerged in the region that is now afghanistan, pakistan, and west india?

The Gupta Empire took over after the Mauryans, between approximately 320 and 550 CE. The Gupta were much more decentralized than the Mauryans, and some of this led to their demise midway through the 6th century. The Gupta were also known for their architecture and literary prowess, with many important texts being canonized during their reign.