The actor, who has portrayed Mohinder Suresh since Heroes started in 2006, will replace Eric Lively, who recently departed the cast of the pilot.
The project revolves around Piper Perabo's character, a CIA trainee called Annie Walker who has a mysterious ex-boyfriend.
Other stars attached to the pilot include Ugly Betty's Christopher Gorham, former O.C. actor Peter Gallagher, and Anne Dudek of House fame.
Ramamurthy was previously attached to David Tennant's NBC pilot Rex Is Not Your Lawyer, but dropped out earlier this year.