"The posts are lying vacant mainly because of non-availability of suitable candidates and litigation," Culture Minister Mahesh Sharma said in a written reply.
The organisations where the directors' posts are vacant are: National Museum (New Delhi); National Gallery of Modern Art (Mumbai and Bengaluru), Indian Museum (Kolkata) and Salarjung Museum (Hyderabad).
Sharma, however, said, "The process of selection for the vacant posts of directors is ongoing".