What is the 71st amendment to Indian Constitution?

The Seventy-First Amendment to the Indian Constitution included Konkani, Manipuri, and Nepali languages in the Eighth Schedule. With this, the total number of scheduled languages increased to 18. 

Further Reading :

• Schedules of Indian Constitution
• Schedules of the Indian Constitution

To read more about the 8th Schedule of the Indian Constitution, check the linked article.