Rohan has performed with the major orchestras of Europe, USA, Canada, Australia and the former Soviet Union with conductors such as John Barbirolli, Adrian Boult, Zubin Mehta, Seiji Ozawa and William Steinberg, as well as with composers conducting their own works such as Luciano Berio. After the UK premiere of Il Ritorno degli Snovidenia for cello and orchestra Berio said of him: "Your performance of Ritorno is splendid, but besides Ritorno, your sound, your perfect intonation, your phrasing and bowing technique, make you a great performer of any music." As a result Berio wrote for him his final Sequenza, no XIV, for solo cello which, as a tribute to Rohan, includes large sections based on the rhythms of the Kandyan drum of Sri Lanka, an instrument which Rohan himself has played since his childhood in Sri Lanka.

Rohan has worked with Kodaly, Shostakovich, Poulenc and Walton, as well as more recently with many leading contemporary composers such as Pousseur, Xenakis and Berio who have, amongst others, written works for him. His numerous recordings include Vivaldi's Sonatas, Rubbra's Soliloquy for cello and orchestra, Britten's Cello Suites Nos 1-3, John Mayer's Ragamalas & Prabhanda, Xenakis' Kottos and Carter's Figment I and II. Feldman's Trio (Mode Records) appeared in 2009. Rohan's recordings of Berio's Sequenza XIV were released by Mode in April 2006 and by Edition Zeitklang (also including works by Xenakis, Carter, B. A. Zimmermann, Ruzicka, Gelhaar, Pröve and Steinke) in 2010, while 2011 has witnessed release of Harmonic Labyrinth and the first of two volumes of de Saram in Concert

On 15th December 2004 the University of Peradeniya conferred on Rohan the degree of Doctor of Letters Honoris Causa.. A year later, in December 2005 he received the Deshamaniya, a national honour of Sri Lanka, presented by the President.

Since returning to solo work in November 2005 after the years with the Arditti, Rohan has pursued a most challenging exploration of repertoire, collaborators and venues, driven by a profound desire to explore new modes, new composers, new musical cultures and new possibilities worldwide, and inspiring in the process a considerable expansion of the cello repertoire.

Rohan has performed a continuous stream of original works written specially for him in new instrumental combinations such as bassoon & cello (with Pascal Gallois), double bass & cello (with Stefano Scodanibbio), flute & cello (with Carin Levine, Richard Craig, Roberto Fabbriciani), guitar and cello (with Magnus Andersson, Jonathan Leathwood), clarinet, flute & cello (with Tadej Kenig, clarinet), percussion & cello (with Suren de Saram, Jean-Charles Francois, Florent Jodelet, Stephan Froleyks), harpsichord & cello (with Preethi de Silva), voice & cello (with Patricia Rozario).

In September 2007 Rohan and Aki Takahashi had the honour of playing in the presence of Empress Michiko of Japan, herself a talented pianist. Three months later he appeared for the first time in Hanoi to give the world premier of a double concerto for cello, percussion and orchestra by Ton That Tiet. 2009 saw him returning to Yerevan for the first time since the Soviet era, having a week earlier in Cologne given the world premier of Chant, a new work for cello and orchestra by Toshio Hosokawa, in a performance that received a prolonged and resounding ovation. Collaboration with Hosokawa continues with Rohan's extensive participation in the Takefu Festival on Japan's north-west coast. In Los Angeles he has appeared with 'Con Gioia' in a programme that included the US premier of Param Vir's Beyond The Reach Of The World for solo cello alongside works by J.S. Bach, Pietro Locatelli and Luigi Boccherini.

One continuing theme has been the Aberdeen Sound Festival, of which he is a founding patron along with Dame Evelyn Glennie and James MacMillan. He has also made regular appearances in Los Angeles as part of the Dilijian concert series, working with Movses Pogossian and Kim Kashkashian.

It is noteworthy that the classical repertoire has fitted well in programmes alongside the new contemporary works, with Bach in particular playing a prominent part. Repeated requests for Rohan to play the Kodaly solo sonata, the Berio Sequenza XIV and Xenakis’ Kottos have caused these works to become classics in Rohan's own repertoire and blazed a trail for other cellists to follow. Indeed, many have beaten a path to his door to study Berio’s Sequenza XIV with him, as well as Xenakis’ Kottos, with students coming from as far afield as Brazil, Australia, USA and Canada, not to mention many European countries.

One line of development has been working as part of a trio with bassoonist Pascal Gallois (now replaced by Elise Jacobsberger) and Magnus Andersson (guitar). The first work written for this trio was by John Stringer of York University, followed by a succession of other works especially written for and premiered by them. At the same time, Rohan and Magnus continue to give regular recitals together as a duo, including new works written for them.

Alongside his performing life, Rohan has been in demand as teacher and adjudicator. Summer 2016 saw him teaching at an inaugural summer course in San Marino to which he will return in July 2017. Similarly May 2017 will see him once again teaching and giving a solo recital at the Conservatorio Monteverdi in Bolzano, Italy. Other venues on his teaching schedule have included the Cervantino Festival, Mexico; Impuls Festival, Graz, Austria; Musik Akademie Basel, Switzerland; Universities of Minnesota, Buffalo NY and in Seattle USA; Dartington Summer School and the Royal Northern College of Music, Manchester, UK.

A highlight of this most recent period has been the 2013 publication of his book Conversations written together with Joachim Steinheuer, eminent musicologist at the University of Heidelberg, Germany. The book is written in English and published by Wolke-Verlag, Germany.

In November 2016, in recognition of his exceptional contribution to music, the Sri Lanka Foundation of Los Angeles honoured him with their Lifetime Achievement Award.

During the pandemic lockdown, Rohan worked on standardising notation for his extensive collection of rhythms for the Sri Lankan Kandyan drum, accumulated from his earliest years. Quite by coincidence he was then commissioned to write a piece for Kandyan drum and members of the Birmingham Contemporary Music Group to be performed as part of the celebrations for the Commonwealth Games held in that city in 2022. The work featured Rohan as solo Kandyan drummer accompanied by a string sextet and percussion including ankle bells and finger cymbals. In the central movement, he was partnered by his son Suren in a duet for Kandyan drum and western drumkit, always based on the ancient Kandyan drum rhythms. This work was premiered in Birmingham on September 4th 2022.