Sawadee Khrub!
Where in Thailand are you located? There are a number of shops with dynos in Bangkok that can tune your ER6n.
Personal favorite is Dirt Shop, followed by Red Baron then TPI and Jammer. There are probably some others, but those are the ones I know of.
BUT, your ER6n must be a 2009+ model, so you should have a PCV, yes?
Why not buy an autotune to go with your PCV? It will allow you to tune your bike yourself and save you the time and expense of going to a dyno shop.
Just my two satang
Chok dee!
Tony