Where to remap ?? How much it cost ?? And how many up increase ??
if you mean by ecu tuning, you can do it yourself. you will need to get logging software (evoscan) and ecuflash, and wideband o2 sensor. it'll cost you, but it'll save you $$ for the long run, and you get know your own tuning more.
can't say how much increase. first step of tuning is to reduce knocking (can be quite bad for stock and running low octane petrol) as low as possible, some call it de-tune, but the car may become more responsive and healthier for the long run.
i dont know the tuning price in Malaysia. over here, it costs around 1300$ to get it tuned the first time, touch up tuning from 300$.