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

Yes, the two civilizations both existed around 1947 CE.

Which lasted longer, Vietnam or Republic of India?

Vietnam lasted longer (81 years).

Vietnam: Asya; Republic of India: Güney Asya

Vietnam (1945 CE – present) and Republic of India (1947 CE – present) lived in the same era.

	Vietnam	Republic of India
Period	1945 CE – present	1947 CE – present
Duration	81 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	96,462,106	1,400,000,000
Rulers	15	8

Socialist Republic of Vietnam · Asia

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

Did Vietnam and Republic of India exist in the same era?: Yes, the two civilizations both existed around 1947 CE.
Which lasted longer, Vietnam or Republic of India?: Vietnam lasted longer (81 years).
Which regions did Vietnam and Republic of India rule?: Vietnam: Asya; Republic of India: Güney Asya