The correct answer is option 3. The statement "Indian is a sectoral dialogue partner of ASEAN" is not correct. ASEAN, or the Association of Southeast Asian Nations, was indeed established in Bangkok in 1967 by the five original member countries, which are Indonesia, Malaysia, Philippines, Singapore, and Thailand (option 1 is correct). Singapore is indeed one of the original members of ASEAN (option 2 is correct). However, India is not a sectoral dialogue partner of ASEAN. ASEAN has sectoral dialogue partnerships with countries like Australia, China, Japan, and South Korea, but India is not one of them.

It is important to note that as of the time of writing, there are ten members of ASEAN. The original five member countries were later joined by Brunei in 1984, Vietnam in 1995, Laos and Myanmar in 1997, and Cambodia in 1999 (option 4 is correct).