"This was the only time in independent India that a referendum-like procedure was used to ascertain people’s wishes on a subject."

Which state is being referred to here?

Goa

In January 1967, the Central Government held a special ‘opinion poll’ in Goa asking people to decide if they wanted to be part of Maharashtra or remain separate. This was the only time in independent India that a referendum-like procedure was used to ascertain people’s wishes on a subject.