International Master (2018), Grandmaster (2018).
In 2015, Arjun won a silver medal in the 2015 Asian Youth Championship in Korea. He won his FIDE Master title at the Asian Youth Chess Championship's U14 group(2) in 2017 and previously won a Candidate Master title from the same qualifier event 2 years earlier. At the 2017 WYCC U-14, he scored nine points(1) to win clear 2nd (behind only Dambasuren Batsuren who won) after 11 rounds.
In 2018, he became the first grandmaster from Telangana state.He earned that title when he was still just 14 years old
In 2021 he became the first Indian to qualify for the knockouts of Champions Chess Tour 2021 ahead of Alireza Firouzja, Daniil Dubov, Peter Svidler and Vidit Gujrathi, eventually losing to Levon Aronian in tie breaks in a closely fought match.
In the star studded https://lindoresabbeyblitz.fide.com... he tied for second/third with Caruana and behind winner Shevchenko, at 13.5 points out of 18, after leading for most of the tournament.
In Nov 2021 he won the Tata Steel India Rapid & Blitz (2021) Rapid: 1. Arjun Erigaisi 6.5
2-4. Levon Aronian, Praggnanandhaa Rameshbabu, Vidit Gujrathi 5.5 etc..
References / Sources
(1) http://chess-results.com/tnr297050.... (he went unbeaten throughout the 2017 Montevideo WYCC tournament points in the U-14 section), (2) http://chess-results.com/tnr119506.... (2013 WYCC U10 score was 7/11), (3) http://ratings.fide.com/view_source...
Wikipedia article: Arjun Erigaisi