Ghazwa e Hind

Ghazwa-e-Hind or the final battle of India is an Islamic term mentioned in some "good" hadiths in particular Sunan an-Nasa'i predicting a final and last battle in India and as a result, a conquest of the whole Indian sub-continent by Muslim warriors.

It was narrated that Thawban, the freed slave of the Messenger of Allah (ﷺ), said:
"The Messenger of Allah (ﷺ) said: 'There are two groups of my Ummah whom Allah will free from the Fire: The group that invades India, and the group that will be with 'Isa bin Maryam, peace be upon him.'"

Reference :
Sunan an-Nasa'i 3175
Book 25, Hadith 91