Kani was born in Trivandrum, Kerala to social activist and rationalist parents Jayasree AK and Maitreya Maitreyan. Her parents had dropped their last names to erase the social hierarchy marker that comes with last names in India. At 15, she invented her last name “Kusruti” (meaning “mischievous” in Malayalam) to fill in a requirement in her class 10th exam application. She grew up in Thiruvanthapuram, where she got introduced to the Abhinaya Theatre Research Centre, "a common platform for theatre practitioners”. She later moved to Thrissur, where she enrolled in the theatre arts program at the Thrissur Drama School, between 2005 and 2007. She completed her theatre education at the L'École Internationale de Théâtre Jacques Lecoq, where she studied physical theatre for two years.

At Abhinaya, Kusruti made her theatre debut in Baudhayana's classic farce Bhagavadajjukam. She played the lead role of Vasantsena in the production from 2000 to 2006. The play toured across theatre festivals, including the Bharat Rang Mahotsav and the International Theatre Festival of Kerala. She rendered the part of Kamala in Jyotish M G’s stage adaptation of Herman Hesse' Siddhartha. In 2007, the production was invited to the Villeneuve en Scene Festival d’Avignon.In 2009, after returning from L'École Internationale de Théâtre Jacques Lecoq,

Kusruti appeared in the anthology film Kerala Cafe, in the segment “Island Express” directed by Shankar Ramakrishnan. In 2010, she played a Naxalite in the Mohanlal starrer Shikkar, but her nuanced rendition of a sex worker in the 2010 film Cocktail got her noticed by mainstream audiences.

In December 2010, Kani collaborated on creating ‘Las Indias’, a "mega performance event" directed by the thespian and theatre pedagogist Elias Cohen. The performance was staged in a bus, that was designed for the production. The Indo-Latin American theatre company, the Singing Sticks Theatre Ensemble evolved out of Las Indias. The bus that was originally created for Las Indias, was used once again for an interactive theatre roadshow 'Tsunami Express: Highway of Hopes’, which Kusruti collaborated on making.

In 2011, Kani joined the renowned touring theatre company Footsbarn to work on a new production of Shakespeare’s Tempest. She played Miranda in the resulting performance “The Indian Tempest”. After touring Ireland, Spain, France, Portugal and India, the production opened at Shakespeare’s Globe in 2013.

Kusruti researched, co-developed and acted in the Indo-Polish production 'Burning Flowers - 7 Dreams of a Woman', directed by Pawel Szkotak and produced by Teatr Biuro Podróży.^[13]

In 2015, Kani became a household presence with the soap opera Eswaran Sakshiyayi, directed by K K Rajeev. She played the part of Advocate Tresa, a lawyer who joins in on the investigation for her brother’s murder.^[7]

Kusruti has acted in Vipin Vijay’s upcoming feature film, due for a 2017 release.

Kusruti’s mother Dr.Jayasree AK, a community health specialist and a social activist, lectures at Pariyaram Medical College, and is a regular guest on talk shows. Her father Maitreya Maitreyan has worked for, and led, several human rights movements in Kerala.

Kani Kusruti lives in Mumbai with her partner, the filmmaker and science communicator Anand Gandhi. She identifies herself as an atheist and a rationalist.^[14][15]