The Chennai-based player was paired with Grand Master Prujjsers Roland in the final round, which ensured that he would achieve the feat. After beating GM Moroni Lica Jr in the eighth round, he needed to play an opponent above rating of 2482 in the next round to make his third GM norm.
Five-time world champion Viswanathan Anand, the country's first GM, congratulated Praggnanandhaa on his achievement.
"Welcome to the club & congrats Praggnanandhaa!! See u soon in chennai," he tweeted.
Welcome to the club & congrats Praggnanandhaa!! See u soon in chennai?
— Viswanathan Anand (@vishy64theking) June 24, 2018
Viswanathan Anand was 18 years old when he earned his third norm.
Meanwhile, Pragga's coach R B Ramesh described it as a fantastic achievement.
"Fantastic achievement of course. Feeling proud that one of my students could achieve this. It was a collective effort from parents, who stood by him in tough times, sponsors Ramco group, ONGC and his school," he told PTI.
"BIG Relief! Congratulations @rpragchess . Great inspiration personally working with you! He travels an hour each way to attend lessons. Great commitment from the parents. Thanks to sponsors Ramco and Mr. Venkaraman Raja too!," he also tweeted.
Ramesh said Praggnanandhaa had the chance to break Karjakin's record last year and did come close to making the GM norms but missed out narrowly in the end.
"Last year, Praggna has come close to making the GM title but now that it has been achieved, we are all very happy. He can only get better from here," said Ramesh, whose movement is hindered by polio.
He also said there would be greater expectations from the youngster now that he has become a GM. "Pressure is something every sportsman should learn to live with, can't complain about that," he added.
Praggnanandhaa's father A Ramesh Babu said he was overjoyed with Pragga's achievement.
"I am overjoyed. He has put in a lot of hard work. Credit goes to my wife, who accompanies him to tournament and is very supportive. Due must be given to coach (Ramesh sir)," he added.
Praggnanandhaa's sister Vaishali is also a WIM and has won the world under-14 and 12 titles previously.
The fourth spot in youngest Grandmasters is also held by an Indian – Parimarjan Negi at 13 years, 4 months and 22 days.
Praggnanandhaa even bettered the record held by current World Chess Champion Magnus Carlsen who became a GM when he was 13 yrs, 4 months old.
To become a Grandmaster, one needs to earn three norms and an Elo rating of 2500.
Pragnnandhaa had won his first GM norm at the World Junior Championships in Tarvisio, Italy in 2017. The second norm was achieved after winning the Herkalion Fischer Memorial GM Norm tournament in Greece this year in April.
After being paired with Dutch GM Roeland Pruijssers for the final round, Praggnanandhaa was assured of a third norm irrespective of the result of the match. He is placed joint-top on the table at the end of 8 rounds, with 6.5 points.
By beating Moroni Luca Jr in the eighth round, Pragnnandhaa needed to play an opponent above of rating of 2482 in the final round to make his third norm.
He was paired with GM Prujjsers Roeland, rated 2514, which made it possible.
To become the youngest Grandmaster, he needed to complete all the norms and touch an Elo rating of 2500 before March 10 this year which would have taken him past Karjakrin but destiny had other plans for the young boy.
Youngest grandmasters in history:
1. Sergey Karjakin (Ukraine) 12 years, 7 months
2. R Praggnandhaa (India) 12 years, 10 months
3. Nodirbek Abdusattorov (Uzbekistan) 13 years, 1 month
4. Parimarjan Negi (India) 13 years, 4 months
5. Magnus Carlsen (Norway) 13 years, 4 months