Kher, 62, will play former prime minister Manmohan Singh in the film adaptation of Sanjaya Baru's book of the same name.
The actor tweeted, "Thank you all for your love, warmth & support for the #FirstLook of #TheAccidentalPrimeMinister. Your response has been overwhelming."
The film is being directed by Vijay Ratnakar Gutte and produced by Ashoke Pandit and Sunil Bohra. It is slated to release next year.