can you make a close combat double target mind control attack on two adjacent enemy characters?

No. As a general rule (there are exceptions) close combat attacks do not have more than one target. The number of a figure has applies only to ranged attacks.

Tarnish

Under normal circumstances? No. However, if you were to equip a figure (say Purple Man, Moondragon, N'astirh) with the 'Elite Sniper' feat card, then yes, you could.

Something to think about

While this can be done, the guy is still doing ranged attacks.

thought the MC can done in close combat attack such as Puppet Master does as he does not have a range? Can MC two opponents while close combat?

You can only use Mind Control on one target if using Mind Control in close combat.

And remember that MC defaults to a 4 range if the figure has no range.

Tarnish