Colossal statues of which rulers have been found installed in a shrine at Mat near Mathura?

The correct answer is Kushanas.

Key Points

• Huge statues of Kushana emperors have been discovered erected at a sanctuary at Mat, close to Mathura (Uttar Pradesh).
• Additionally, a shrine in Afghanistan contained similar figures. This, in the opinion of some historians, shows that the Kushanas thought of themselves as divine.
• Many Kushana kings also took the term devaputra, which means "son of god," presumably as a result of Chinese emperors referring to themselves as sons of heaven.
• Evidence of larger nations, including the Gupta Empire, dates to the fourth century.
• Many of these were dependent on samantas, or self-sufficient men who controlled local resources like the land.​

Important Points 

• Kushanas, who ruled over a wide kingdom spanning from Central Asia to northwest India, lived in the first century BCE or first century CE.
• The inscriptions and textual traditions have been used to reconstruct their history.
• Perhaps their coinage and art best demonstrate the ideas of kingship they intended to represent.