The 81-year-old, Kader Khan has reportedly developed breathing issues and the doctors have transferred him from regular ventilator to BiPAP ventilator.
Megastar Amitabh Bachchan took to Twitter to pray for Khan's well being and recovery.
"Kader Khan... actor writer of immense talent... lies ill in Hospital... Prayer and duas for his well being and recovery... Saw him perform on stage, welcomed him and his prolific writing for my films. Great company, a libran and many not know, taught Mathematics," Bachchan tweeted.
Bachchan and Khan worked together on films such as "Do Aur Do Paanch", "Muqaddar Ka Sikandar", "Mr. Natwarlal", "Suhaag", "Coolie" and "Shahenshah".
Born in Kabul, Afghanistan on October 22, Khan made his acting debut in 1973 with Rajesh Khanna's "Daag". Prior to that he had written dialogues for Randhir Kapoor-Jaya Bachchan's "Jawani Diwani".
As a screenwriter, Khan frequently collaborated with Manmohan Desai and Prakash Mehra. His films with Desai include "Dharam Veer", "Ganga Jamuna Saraswati", "Coolie", "Desh Premee", "Suhaag", "Parvarish" and "Amar Akbar Anthony" and films with Mehra include "Jwalamukhi", "Sharaabi", "Lawaaris", "Muqaddar Ka Sikandar".
Khan has also penned dialogues for "Coolie No. 1", "Main Khiladi Tu Anari", "Karma" and "Sultanat".
The actor has till now featured over 300 films. He has written dialogues for over 250 movies.