Early life and youth career Rai was born in
Pakyong, a small village in
Sikkim. He always liked to play football, even as a kid. He got interested in the game by his uncle, who played football himself. He was selected by a local academy in his state at the age of 12. He travelled to
Delhi to play in the
Subroto Cup, spent a couple of years there before joining the
Pune Academy which was later converted into the
Pune City Academy. Since,
Pune City already had experienced players in the right-back position, they loaned him out to
Indian Arrows.
Indian Arrows 2017–18 season On 29 November 2017, Rai was selected to play for the
Indian Arrows, an
All India Football Federation owned team that would consist of
India under-20 players to give them playing time. He made his professional debut for the side on 26 December 2017, against
Shillong Lajong. He started and played the full match as
Indian Arrows won 3–0. In his debut season, Rai made ten appearances, one in the
2018 Indian Super Cup for the
Arrows. Although they finished bottom of the table in the
I-League, they impressed with their gameplay and football.
2018–19 season On 5 November 2018, he scored his first goal for the club in only his second appearance of the season against
Shillong Lajong, which eventually was the winning goal as the
Arrows won 1–0. He featured in all 20 matches of the
2018–19 I-League campaign and also a couple in the
2019 Indian Super Cup, as he became a permanent fixture in the right full-back position. The team improved from the season before and picked up 21 points to finish eighth in the points table.
Hyderabad 2019–20 season Rai went back to the reserves team of
Pune City, and when the club was dissolved in the summer of 2019, their replacement club
Hyderabad signed him for their first team. He made his professional debut for the club on 25 October 2019, against
ATK in a 5–0 loss. On 8 December 2019,
Hyderabad head coach
Phil Brown heaped praise on Rai after he put in a splendid display in the right-back position, in their narrow 1–0 defeat against
Goa. The debut season of
Hyderabad was a devastating one for the club and the fans, most of the Indian players didn't play in their preferred position and one of them was Rai. He played as a left-back, right-back and on the wings, too. He played 14 games for them in the
2019–20 Indian Super League. Due to the unstableness in the squad, tactics and many other factors, he wasn't able to perform up to the mark and couldn't give his best. On 17 February 2020, Rai signed a three-year extension with the club, till May 2023.
2020–21 season Rai and
Hyderabad set the stage alight in the
2020–21 League season, under the stewardship of
Manolo Márquez. The second season was a huge improvement for the outfit from the inaugural 2019-20 campaign, where they had finished last in the standings. Despite staying in contention for the playoffs throughout, the Nizams missed out on qualification on the final day due to a string of draws and dropped points. Rai was in sensational form throughout the season until he picked up a season-ending knee injury against
Kerala Blasters, on 16 February 2021. The right-back's industry on the flank and constant threat in the attacking third made him a tough operator for the opposition to contain. He featured in 18 matches of the
2020–21 Indian Super League campaign and also racked up two assists in the process. Head coach
Márquez called Rai "the most improved player" of last season.
Mohun Bagan Rai moved to another Indian Super League side
Mohun Bagan in 2022. He made his debut for the club on 20 August against
Rajasthan United at the
131st edition of
Durand Cup and they were defeated by 3–2. ==Career statistics==