In my company now is used commonly used 240V supply. But now more in china equipment, the supply will changed to 220V.
Now in Malaysia, 240V is with Sirim approved, but is 220V is not sirim approved. So now, is the 240V spot lighiting can be used 220V supply? Any effect on it? Do I need to recalculated again the Amp for the spot lighting?

You need to check the manufacturer specifications of the lighting you have to see if it will work properly on 220 volts, and if it will be operating within Sirim guidleines.

Expect the lamps to be a bit dimmer.. approx. 9%, but other than that there shouldn't be any issues.

I agree with Missouri.I run 277v metal halides on 230v(Canada standard voltage)no problem,