Since 1987, Simhalan has been part of most of the productions of the Indian Chandralekha (dancer) group (1988–1993) and Shobana Jeyasingh dance company (1993–2003) as a dancer and educational/workshop leader. At the same time, Simhalan has worked as a soloist and a choreographer. Simhalan has toured and performed in productions of Wayne McGregor (UK), Richard Alston (UK), Laurie Booth (UK), Roger Sinha (Canada), Mavin Khoo (UK), and was also part of the 2001 Basement Jaxx album and Emergency Exit Arts production RungaRung. In the summer of 2000, Simhalan both choreographed for and performed in the award winning production, Coming of Age, directed by Keith Khan.
Simhalan's work in television and film includes Check by Amarjeeth Singh, and Away Game, a BBC production. Chathi (means cheat in Malayalam), her physical theatre choreography based on the warriors of Northern Ballads like Aromal Chekavar, Chathiyan channthu etc. of 16th-century in kerala, has toured in the United Kingdom and Europe. Recently, she directed and performed Ghost, a street theatre act and video installation at the Somerset House. She art directed and performed SPILT, a video installation for London Mela. Football and Spare Rib where toured till end 2009 in South East Asia, Europe and the Americas. Currently She runs awareness programmes across South India(setting up programmes for integrating good health through Kalaripayattu, Yoga and Pilates in South Indian educational system, closely working with varied NGO's and Government bodies.