2017, Sethu appeared as Aisha in two episodes of Doctor Foster. In 2018, Sethu starred as DS Mishal Ali for six episodes in the BBC apocalyptic TV crime series Hard Sun.

In 2019, Sethu performed as a series regular in season seven of Strike Back: Revolution as Lance Corporal Manisha Chetri of the British Army. In 2022, She played rebel Cinta Kaz in both seasons of ''Andor''.