please help me to fix my hyundai accent 2013 1.6L there is low rpm still 630 to 660
 

Please help me to fix my problem that my hyundai accent 1.6L 2013 manual transmission there is low RPM when my AC switch it on the rpm there is no reaction. Any idea or suggestions will appreciated. Thank you

The vehicle computer is supposed to adjust the engine idle speed according to the anticipated load on the engine.It sounds like that info either isn't getting to the PCM (Powertrain control module) or the PCM is not sending the signal to the throttle control system or the throttle control is not reacting .This needs to be verified and the only way to accomplish this requires a capable scan tool.

Hi, Sir Good evening. If we bring it to the repair shop how much possible cost to fix this problem? Thank you.

Different areas have different labor rates, then depending on how long it takes the person doing the work, to find the exact cause. Sometimes it can be quick and other times it can take a lot of time. Then depending on what caused the problem is cost of the part(s), time to repair and so on.
If it was something like removing a part and installing a new one that is done frequently,an approx estimate is usually available. When looking for a problem that can be elusive, even the best tech can consume considerable time to locate and verify. Maybe you can inquire from a few shops in your area and get some idea of what they would charge.