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

Yes, the two civilizations both existed around 1947 CE.

Which lasted longer, Japan or Republic of India?

Japan lasted longer (158 years).

Japan: Asya; Republic of India: Güney Asya

Japan (1868 CE – present) and Republic of India (1947 CE – present) lived in the same era.

	Japan	Republic of India
Period	1868 CE – present	1947 CE – present
Duration	158 years	79 years
Region	Asya	Güney Asya
Capital	—	Yeni Delhi
Type	Country	Republic
Government	—	Federal Parlamenter Cumhuriyet
Religion	—	Hinduizm, İslam, diğerleri
Language	—	Hintçe, İngilizce
Peak population	126,264,931	1,400,000,000
Rulers	111	8

Japan · Asia

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

Did Japan and Republic of India exist in the same era?: Yes, the two civilizations both existed around 1947 CE.
Which lasted longer, Japan or Republic of India?: Japan lasted longer (158 years).
Which regions did Japan and Republic of India rule?: Japan: Asya; Republic of India: Güney Asya