In October 2018, he was named in Oman's squad for the 2018 ICC World Cricket League Division Three tournament in Oman.[6] He played in Oman's opening fixture of the tournament, against Kenya on 9 November 2018.[7] In December 2018, he was named in Oman's team for the 2018 ACC Emerging Teams Asia Cup.[8]
He was a member of Oman's team for the 2019 ICC World Cricket League Division Two tournament in Namibia,[9] and made his List A debut against the United States in the same tournament on 20 April 2019.[10][11] Oman finished in the top four places in the tournament, therefore gaining One Day International (ODI) status.[12] Kumar made his ODI debut for Oman on 27 April 2019, against Namibia, in the tournament's final.[13][14]
In September 2019, he was named in Oman's squads for the 2019–20 Oman Pentangular Series and the 2019 ICC T20 World Cup Qualifier tournament.[15] He made his Twenty20 International (T20I) debut for Oman, against Hong Kong, on 5 October 2019.[16] In November 2019, he was named in Oman's squad for the 2019 ACC Emerging Teams Asia Cup in Bangladesh.[17] In September 2021, he was named in Oman's squad for the 2021 ICC Men's T20 World Cup.[18]
In July 2023, Kumar played in a World Cup Qualifying match against the West Indies and was the top-scorer of the match.[19]
