Visa Extension

I am Working in Config Systems

Visiting Seoul for the project work...

But I got  visa only for 3 months.. unfortunately didn't apply for

Multiple entry visa..

I wanted to extend my visa .. Is it possible for me to extend my visa from there only

or i should get back to India and then apply

Regards in advance...

In between travelling to Japan..Tokyo..
But most of the work will be Seoul Centric...