Did Iran and Republic of India exist in the same era?

Yes, the two civilizations both existed around 1947 CE.

Which lasted longer, Iran or Republic of India?

Iran lasted longer (101 years).

Iran: Asya; Republic of India: Güney Asya

Iran (1925 CE – present) and Republic of India (1947 CE – present) lived in the same era.

	Iran	Republic of India
Period	1925 CE – present	1947 CE – present
Duration	101 years	79 years
Region	Asya	Güney Asya
Capital	—	Yeni Delhi
Type	Country	Republic
Government	Cumhuriyet	Federal Parlamenter Cumhuriyet
Religion	—	Hinduizm, İslam, diğerleri
Language	—	Hintçe, İngilizce
Peak population	82,913,906	1,400,000,000
Rulers	15	8

Islamic Republic of Iran · Asia

The world's largest democracy. It gained independence through Gandhi's nonviolent resistance movement. Unity in diversity.

Did Iran and Republic of India exist in the same era?: Yes, the two civilizations both existed around 1947 CE.
Which lasted longer, Iran or Republic of India?: Iran lasted longer (101 years).
Which regions did Iran and Republic of India rule?: Iran: Asya; Republic of India: Güney Asya