He received training in animation techniques from Clair Weeks of Walt Disney Studios, under the US Technical Aid program.

Another important person to join at the same time was Bhimsain Khurana, who also became a notable animator (Ek Anek Aur Ekta).

[9] Mohan started out by doing character design and story boards for This Our India, an animated film adapted from a book by Minoo Masani.

In 1972, he established his own production company, Ram Mohan Biographics, which worked on commercials, and the animated feature Ramayana: The Legend of Prince Rama (1992), which he co-directed in collaboration with Yugo Sako from Japan.

Chopra's Pati Patni Aur Woh (1978), a title sequence for Satyajit Ray's Shatranj Ke Khilari, a sequence for Mrinal Sen's Hindi film, Bhuvan Shome, and for films such as Biwi-O-Biwi, Do Aur Do Paanch and Kaamchor.