Rajan Kumar, a left-arm fast bowler from Haridwar, looks up to Australian speedster Mitchell Starc as his idol. Rising through the ranks of junior cricket, Rajan swiftly transitioned to the senior level. Uttarakhand's decision to grant Rajan his debut cap proved fruitful as he showcased his talent with stellar performances.

During his debut domestic season, Rajan emerged as Uttarakhand's top wicket-taker in the Syed Mushtaq Ali Trophy 2022-23, securing 10 wickets from 7 games. Following this success, he made his List-A debut in the 2022-23 Vijay Hazare Trophy, where he made an immediate impact with three wickets and continued to shine throughout the tournament.

Rajan's achievements reached new heights when Bengaluru acquired him in the 2023 Indian T20 League auction. Continuing his upward trajectory, he achieved a significant milestone in Uttarakhand’s last game of the 2023-24 Vijay Hazare Trophy, registering figures of 5 for 28, marking his maiden five-wicket haul.

With his impressive performances, Rajan earned his first-class debut against Madhya Pradesh in the Ranji Trophy 2023-24, where he impressed by claiming six wickets across four innings. Although Rajan was on the bench for the entirety of the 2023 Indian T20 League, his exploits in the domestic circuit suggest that the left-arm seamer is poised to make his debut in the upcoming season.