Explanation:

India is a member whereas Mongolia is an observer state at the Shanghai Cooperation Organisation (SCO). 

• Other Forums of which both the countries are members: Asia-Europe Meeting (ASEM), World Trade Organisation (WTO).

Defence Cooperation between India and Mongolia

• Joint defence exercises code-named Nomadic Elephant.
• India is also an active participant in an annual week-long joint training exercise called the Khaan Quest, hosted by Mongolia. 

Hence only statement 2nd is correct.