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

Yes, the two civilizations both existed around 1971 CE.

Which lasted longer, Bangladesh or Republic of India?

Republic of India lasted longer (79 years).

Bangladesh: Asya; Republic of India: Güney Asya

Bangladesh (1971 CE – present) and Republic of India (1947 CE – present) lived in the same era.

	Bangladesh	Republic of India
Period	1971 CE – present	1947 CE – present
Duration	55 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	163,046,161	1,400,000,000
Rulers	18	8

People's Republic of Bangladesh · Asia

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

Did Bangladesh and Republic of India exist in the same era?: Yes, the two civilizations both existed around 1971 CE.
Which lasted longer, Bangladesh or Republic of India?: Republic of India lasted longer (79 years).
Which regions did Bangladesh and Republic of India rule?: Bangladesh: Asya; Republic of India: Güney Asya