In which year did India officially join the Shanghai Cooperation Organization (SCO) as a full-fledged member?

2017

The correct answer is Option 4 - 2017

India officially joined the Shanghai Cooperation Organization (SCO) as a full-fledged member in the year 2017.
India became a full-fledged member of the Shanghai Cooperation Organization (SCO) in 2017, marking a significant milestone in its engagement with regional and global multilateral forums. Here's an explanation of India's membership in the SCO
India's journey towards full membership in the SCO began in 2005 when it was admitted as an observer state. Over the years, India actively participated in SCO activities and engaged with member states on various issues of mutual interest. In 2017, India, along with Pakistan, became a full-fledged member of the SCO, expanding the organization's geographical reach and influence.

The Shanghai Cooperation Organization (SCO) currently has 9 member states as of April 4, 2024:

China
India
Kazakhstan
Kyrgyzstan
Pakistan
Russia
Tajikistan
Uzbekistan
Iran