The following pair is not correctly matched:

Samudragupta: Nagarjuna

While Samudragupta and Nagarjuna were both prominent figures in ancient India, they did not live during the same period. Samudragupta was an ancient Indian king who ruled from 335 to 375 CE, during the Gupta Empire, while Nagarjuna was a Buddhist philosopher and scholar who lived in the 2nd century CE, several centuries before the Gupta Empire. Therefore, the pair is not correctly matched.

The other pairs are correctly matched:

Chandragupta Maurya was the founder of the Maurya Empire, and Kautilya (also known as Chanakya) was his chief advisor and author of the Arthashastra, an important treatise on statecraft and governance.

Kanishka was a prominent emperor of the Kushan Empire, and Asvaghosha was a Buddhist scholar and poet who wrote several works during Kanishka`s reign.

Harshavardhana was an ancient Indian emperor who ruled over a large part of northern India, and Banabhatta was a Sanskrit poet who wrote the famous work, Harshacharita, which chronicles the life and reign of Harshavardhana.