Which of the following states was created in 1966?

Punjab

Delhi was made a Union Territory in 1956.
Gujarat and Maharashtra were formed as separate states in 1960.
Punjab and Haryana were made as separate states in 1966.

From the late 1950s, people speaking the Punjabi language started agitating for a separate State for themselves. This demand was finally accepted and the states of Punjab and Haryana were created in 1966. Later, the States of Chhatisgarh, Jharkhand and Uttaranchal (now Uttarakhand) were created.