It's Jayant Yadav.
He came to bat at No 9 for India in the fourth test against England at the Wankhede Stadium in Mumbai in 2016, made his first century in Test cricket on day 4 of the match. The Haryana player just appeared in the opening test of that series and showed an exceptional performance both with the bat and the ball.
Jayant came to bat at 364/7 after the dismissal of Ravindra Jadeja. The 26-year-old completed his maiden test century by taking a single off the fifth ball of the 174th over which was bowled by Chris Woakes. As he reached his maiden century, a huge crowd of Wankhede stadium applauded him very warmly. But he soon got out, stumped, off the bowling of Adil Rashid in the 177th over.
He made 104 off 204 balls, which included 15 fours. Yadav became the 16th batsman to score a hundred at No. 9 in international cricket.
Before Jayant Yadav, the previous highest score by an Indian batsman at the same position was 90 runs by Farokh Engineer against New Zealand at Chennai in 1965 though the highest score at No. 9 belongs to Ian Smith, a former cricketer of Newzealand who made 173 off 136 against India at Auckland in 1990.
During this memorable inning, he had a great partnership of over 200 runs with Virat Kohli who made his third test double century earlier in the same match. In this test with the help of Jayant and Kohli's batting and R Ashwin's bowling performances, India won by an innings and 36 runs.
A Big Thumps-up For Record Makers!!!